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压力开关, 液位开关, 流量开关& 传感器, 电磁阀 - Gems Sensors & Controls

压力开关, 液位开关, 流量开关& 传感器, 电磁阀 - Gems Sensors & Controls

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3160 系列中高压力传感器

压力接口“One Piece”一体化全316L设计，无焊接、无充油、无额外密封

汽车电子高等级EMC测试，高绝缘，高耐压

压力范围0~20BARG至0~900BARG

通过防爆认证

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3560 系列防结冰压力传感器

储氢供氢系统应用

储氢装置、加氢设备、氢气压缩机、燃料电池测试系统、燃料电池系统

 

●   接液部件全316L 材料，防氢渗、氢脆

●   压力范围0~5 BARG，表压绝压可选

●   通过汽车电子高等级EMC测试      

●   满足燃料电池应用中高绝缘耐压的要求

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液位开关|传感器

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电磁阀

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XM/XT-700 系列连续液位传感器

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LS-700 系列多点液位开关

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LS-350 系列多点液位开关

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CAP-300 冷却液液位传感器

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ELS-950 系列单点液位开关

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3100/3200系列压力传感器

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3500系列低压压力传感器

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3510系列低压压力传感器

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3560系列防结冰压力传感器

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3160系列压力传感器

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3160EP系列隔爆型压力传感器

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RFO型电子流量传感器

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FT-110系列涡轮流量传感器

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FS-380系列流量开关

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FS-927系列流量开关

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AG系列电磁阀

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DG系列电磁阀

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AS系列电磁阀

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E与EH系列电磁阀

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TM-950系列温度传感器

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PDTF系列温度开关

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INDUSTRY

行业应用

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氢能及燃料电池

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制冷设备

水和污水处理

石油和天然气

锅炉控制

通用工业

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工程机械

Gems™ Sensors & Controls不断致力于概述工程机械（OHV）行业流体传感器的设计和制造工艺已有50多年历史。凭借数十年的应用经验，Gems对复杂的OHV应用具有独到的眼光，在流体传感器中...

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氢能及燃料电池

压力传感器作为氢气制备、储存、运输和使用过程中常用的传感器之一，在氢能产业发展中扮演着重要的角色。压力传感器的质量和性能直接关系到氢能产业链各环节的发展水平。

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光伏与半导体

福迪威传感技术积极参与绿色能源的建设，从光伏风力发电，到核能、生物质发电，都可提供成熟的解决方案。

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医疗科学

在Gems Sensors & Controls医疗科学部门看来，流体输送是一门集自然科学、严谨理论和成熟方法于一体的艺术。凭借广泛的特有技术组合和丰富的应用经验，我们能与您一起按时按预算交付成果。

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铁路运输

欧睿国际行业调查“中国铁路运输行业预计到2020年将会持续增长，中国铁路网的建设扩张和客运量的持续增长将支持高速列车制造产业的中长期需求”。增长动力源于中国的快速城镇化进程、内需动力、技术革新需求，环境污染问题所驱动市场替代就有技术和设备，政策法规要求质量和安全性的提高以及海外市场扩展的期望，这些都将为中国铁路行业注入增长动力。

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风力发电

在风力发电机中，液压系统通过控制叶片间距和偏航，确保在任何风力条件下都能输出较大发电量，同时避免风力发电机损坏，传感器在中间发挥了至关重要的作用。要保证风力发电机的机械性能和控制疲劳强度，关键是对这类液压系统的状态进行连续监控。

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制冷设备

随着当今社会工业发展的不断进步，HVAC/R (水冷系统,空气冷却,油分离器)越来越广泛应用于工厂和楼宇系统等工业各领域，拥有一台稳定可靠的传感器则显得尤为重要。

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水和污水处理

Gems™ Sensors & Controls凭借着出色的精度和可靠性，满足各行各业对可靠测量产品的苛刻要求，赢得了个广大客户的广泛认可。水和污水处理行业也不例外。

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石油和天然气

随着全球不断寻求提高油气资源的利用效率，保障运营安全稳定正变得越来越重要。50多年来，Gems Sensors一直致力于为石油和天然气行业提供定制解决方案，起到了举足轻重的作用。

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锅炉控制

挑选合适的电子控制设备并集成在锅炉系统中，不仅过程复杂棘手，而且根据实际应用而变化。对于简单的应用，一个基本的安全继电器就足够。对于更复杂的应用，可以帮助终端用户诊断供热系统故障的多功能控制器是不可或缺的。无论何种应用，您的控制器规格和设计都必须严格遵守当地和联邦法规。作为业内老牌的Warrick系列锅炉控制器制造商，Gems专门撰写了这篇文章，旨在帮助锅炉行业从业人员了解锅炉安全控制相关的规范。

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通用工业

Gems传感与控制产品在全球各地的各行业中已有60多年的销售历史，在全球设有销售办事处和分销网络，提供类型丰富的液位，流量和压力传感器以及微型电磁阀。在北美（ISO：13485）、亚洲（ISO：9001）和欧洲（ISO：9001) 拥有4家通过ISO质量体系认证的制造工厂，每年向顾客提供四百多万个传感器。

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船舶

自1955年成立以来, 凭借出色的精度和可靠性，Gems™ MarineGrade™ 产品通过 UL 、 CSA 以及 FM 等商用船只认证，赢得了商用船舶行业的广泛认可。 Gems 工程师通晓各种船上要求并拥有丰富的应用经验。此外，我们还长期提供定制设计服务，成功交付数百种产品。凭借这些成熟型号的认证图纸，我们拥有现成的方案来解决您的流体指示难题。

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NEWS

新闻资讯

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2023-06-28

邀请函 | Gems捷迈携储氢供氢系统应用解决方案邀您共赴FCVC 2023盛会

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2023-06-28

工程师频道|液位测量传感器，您选对了么？

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2023-05-29

展会速递|精彩不断，Gems全新血液检测系统应用方案实力圈粉

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首届清华大学水泥混凝土博士生论坛圆满落幕 -清华大学土木工程系

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首届清华大学水泥混凝土博士生论坛圆满落幕

发布时间：2020-09-07 点击数：

9月4日，为期两周的首届清华大学水泥混凝土博士生论坛暨Empa第七届水泥化学热力学建模（GEMS）博士生课程（2020.8.24-2020.9.4）圆满落幕！本次论坛由清华大学土木工程系建筑材料研究所孔祥明、李克非老师精心组织，筹备时间长达半年。论坛以水泥化学热力学建模为主题。受全球疫情影响，原计划线下举办的论坛转为线上进行。本次论坛很荣幸邀请到来自Empa的著名学者Barbara Lothenbach、Frank Winnefeld及两位博士后Zhenguo Shi与Bin Ma为主讲教师，来自全国多所高校和研究所的41位研究生参与了本次论坛。近十年来，热力学模拟在水泥化学领域的应用迅速发展。GEMS（Gibbs Energy Minimization Software）作为热力学模拟的主流工具深受众多水泥化学研究者的喜爱。Empa的GEMS课程已举办七届，本次是首次面向国内学生举办。课程分成4个班（2个英文班和2个中文班）同时进行。论坛气氛活跃，反响良好。交流过程中，同学们踊跃发言，积极讨论，并在最后两天做出了精彩的报告。期待他们成为国内GEMS应用的先行者与推广者。感谢来自瑞士Empa四位老师的辛勤付出。祝大家的科研工作蒸蒸日上，硕果累累！GEMS课程（中文版）录像下载：（下载密码GEMs2020）第一讲：课程介绍及水泥化学简介(https://cloud.tsinghua.edu.cn/d/2c18c7b658234384ade5/files/?p=%2F2020-08-24%20GEMS%20course%2C%201st%20lecture%20English-cement-1st%20calc.mp4&dl=1）首先回顾了水泥的生产过程、熟料组成、水化过程及相关化学知识，并通过在GEMS中创建“C3A + CaO + CaSO4”水化体系，使学生对GEMS有初步的了解。 第二讲：单系统类计算(https://cloud.tsinghua.edu.cn/d/2c18c7b658234384ade5/files/?p=%2F2020-08-25%20GEMS%20course%2C%202nd%20lecture%20Chinese%20single%20calculation.mp4&dl=1)首先以石膏的化学平衡为例，简单回顾了热力学建模的相关知识；然后对GEMS的安装进行讲解；最后，以纯C3A系统的水化为例，对GEMS的使用进行讲解。 第三讲：过程（多系统）类计算(https://cloud.tsinghua.edu.cn/d/2c18c7b658234384ade5/files/?p=%2F2020-08-26%20GEMS%20course%2C%203rd%20lecture%20Chinese%20process.mp4&dl=1)以石灰石或粉煤灰掺量对水化产物组成影响为例，对过程类计算的使用方法进行讲解。 第四讲：GEMS数据库(https://cloud.tsinghua.edu.cn/d/2c18c7b658234384ade5/files/?p=%2F2020-08-27%20GEMS%20course%2C%204th%20lecture%20Chinese-database.mp4&dl=1)以Cementdata18为例，对GEMS的热力学数据库及程序结构进行讲解，并演示了溶解度、饱和指数的计算。 第五讲：水泥水化的热力学模拟(https://cloud.tsinghua.edu.cn/d/2c18c7b658234384ade5/files/?p=%2F2020-08-28%20GEMS%20course%2C%205th%20lecture%20Chinese%20hydration%20modelling.mp4&dl=1)基于Parrot-Killoh模型，描述了水泥水化程度随时间的变化规律，并以此预测水泥水化过程中系统的固相组成与液相组成。 第六讲：环境与系统的相互作用(https://cloud.tsinghua.edu.cn/d/2c18c7b658234384ade5/files/?p=%2F2020-08-31%20GEMS%20course%2C%206th%20lecture%20Chinese-durability.mp4&dl=1)以水泥置于氢氧化钠溶液、硫酸钠溶液、二氧化碳气氛等环境为例，介绍如何利用过程类计算描述系统与环境的相互作用。 英文版课程录像下载地址：https://www.empa.ch/web/s308/gems-2020-videos  软件及相关学习资料下载地址：https://www.empa.ch/web/s308/tutorials 

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GEMs（神戸大学グローバル教育管理システム）

GEMs（神戸大学グローバル教育管理システム）

神戸大学では、2018年4月から、神大生の海外留学を支援するため、“GEMs(ジェムズ)”（Kobe University Global Education Management System／神戸大学グローバル教育管理システム）を導入しました。

　神戸大学では、年間約1,000人の学生が大学の海外留学プログラムを活用して留学しています。神大生の在学中の海外体験をもっと身近に、留学手続きをもっと簡単にするため、GEMsが学生の挑戦を支援します。　また、GEMsは、大学教職員の業務も支援します。[学内募集、申請受付、派遣生の選考、合否通知、留学手続き進捗管理、危機管理オリエンテーション出欠や海外旅行保険加入管理、海外渡航届受理、学生相談記録、統計データの作成・閲覧等]

GEMsでは以下のことができます。

☑ 神戸大学が提供する海外留学プログラムの検索・申請

☑ 留学準備～帰国後の手続きの進捗管理

☑ 海外留学のための奨学金の検索・申請

☑ 海外渡航届／留学生の一時帰国届の提出

利用環境：パソコン、スマートフォンで学外からもアクセス可能※情報基盤センターが発行したログインIDとパスワードを利用して、パソコン・スマートフォンからアクセスしてください。言語：日本語・英語

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Gemstone - Wikipedia

Gemstone - Wikipedia

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(Top)

1Characteristics and classification

2Value

3Grading

4Cutting and polishing

5Colors

6Treatment

Toggle Treatment subsection

6.1Early history

6.2Heat

6.3Radiation

6.4Waxing/oiling

6.5Fracture filling

6.6Bleaching

7Synthetic and artificial gemstones

Toggle Synthetic and artificial gemstones subsection

7.1Types

7.1.1Synthetic corundum

7.1.2Synthetic beryls

7.1.3Synthetic quartz

7.1.4Synthetic spinel

7.2Creation process

7.2.1Verneuil flame fusion process (melt process)

7.2.2Czochralski process (melt process)

7.2.3Flux growth (solution process)

7.2.4Hydrothermal growth (solution process)

7.3Characteristics

7.4History

8List of rare gemstones

9In popular culture

10See also

11References

12External links

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Gemstone

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From Wikipedia, the free encyclopedia

Piece of mineral crystal used to make jewelry

Several terms redirect here. For other uses, see Gemstone (disambiguation), Gems (disambiguation), Gem (disambiguation), Jewels (disambiguation), and Precious stone (disambiguation).

Group of precious and semiprecious stones—both uncut and faceted—including (clockwise from top left) diamond, uncut synthetic sapphire, ruby, uncut emerald, and amethyst crystal cluster.

A gemstone (also called a fine gem, jewel, precious stone, semiprecious stone, or simply gem) is a piece of mineral crystal which, when cut or polished, is used to make jewelry or other adornments.[1][2][3] However, certain rocks (such as lapis lazuli, opal, and obsidian) and occasionally organic materials that are not minerals (such as amber, jet, and pearl) are also used for jewelry and are therefore often considered to be gemstones as well. Most gemstones are hard, but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic value. Rarity and notoriety are other characteristics that lend value to gemstones.

Found all over the world, the industry of coloured gemstones (i.e. anything other than diamonds) is currently estimated to be around 10–12 billion US dollars.[4]

Apart from jewelry, from the earliest antiquity engraved gems and hardstone carvings, such as cups, were major luxury art forms.

A gem expert is a gemologist, a gem maker is called a lapidarist or gemcutter; a diamond cutter is called a diamantaire.

Characteristics and classification[edit]

A collection of gemstone pebbles made by tumbling the rough stones, except the ruby and tourmaline, with abrasive grit inside a rotating barrel. The largest pebble here is 40 mm (1.6 in) long.

The traditional classification in the West, which goes back to the ancient Greeks, begins with a distinction between precious and semi-precious; similar distinctions are made in other cultures. In modern use, the precious stones are emerald, ruby, sapphire and diamond, with all other gemstones being semi-precious.[5] This distinction reflects the rarity of the respective stones in ancient times, as well as their quality: all are translucent, with fine color in their purest forms (except for the colorless diamond), and very hard with a hardness score of 8 to 10 on the Mohs scale.[6] Other stones are classified by their color, translucency, and hardness. The traditional distinction does not necessarily reflect modern values; for example, while garnets are relatively inexpensive, a green garnet called tsavorite can be far more valuable than a mid-quality emerald.[7] Another traditional term for semi-precious gemstones used in art history and archaeology is hardstone. Use of the terms 'precious' and 'semi-precious' in a commercial context is, arguably, misleading in that it suggests certain stones are more valuable than others when this is not reflected in the actual market value, although it would generally be correct if referring to desirability.

In modern times gemstones are identified by gemologists, who describe gems and their characteristics using technical terminology specific to the field of gemology. The first characteristic a gemologist uses to identify a gemstone is its chemical composition. For example, diamonds are made of carbon (C) and rubies, of aluminium oxide (Al2O3). Many gems are crystals which are classified by their crystal system such as cubic or trigonal or monoclinic. Another term used is habit, the form the gem is usually found in. For example, diamonds, which have a cubic crystal system, are often found as octahedrons.

Gemstones are classified into different groups, species, and varieties.[8][9] For example, ruby is the red variety of the species corundum, while any other color of corundum is considered sapphire. Other examples are the emerald (green), aquamarine (blue), red beryl (red), goshenite (colorless), heliodor (yellow), and morganite (pink), which are all varieties of the mineral species beryl.

Gems are characterized in terms of refractive index, dispersion, specific gravity, hardness, cleavage, fracture and luster.[10] They may exhibit pleochroism or double refraction. They may have luminescence and a distinctive absorption spectrum. Gemstones may also be classified in terms of their "water". This is a recognized grading of the gem's luster, transparency, or "brilliance".[11] Very transparent gems are considered "first water", while "second" or "third water" gems are those of a lesser transparency.[12]

Material or flaws within a stone may be present as inclusions.

Value[edit]

Spanish emerald and gold pendant at Victoria and Albert Museum

Enamelled gold, amethyst, and pearl pendant, about 1880, Pasquale Novissimo (1844–1914), V&A Museum number M.36-1928

Gemstones have no universally accepted grading system. Diamonds are graded using a system developed by the Gemological Institute of America (GIA) in the early 1950s. Historically, all gemstones were graded using the naked eye. The GIA system included a major innovation: the introduction of 10x magnification as the standard for grading clarity. Other gemstones are still graded using the naked eye (assuming 20/20 vision).[13]

A mnemonic device, the "four Cs" (color, cut, clarity, and carats), has been introduced to help describe the factors used to grade a diamond.[14] With modification, these categories can be useful in understanding the grading of all gemstones. The four criteria carry different weights depending upon whether they are applied to colored gemstones or to colorless diamonds. In diamonds, the cut is the primary determinant of value, followed by clarity and color. An ideally cut diamond will sparkle, to break down light into its constituent rainbow colors (dispersion), chop it up into bright little pieces (scintillation), and deliver it to the eye (brilliance). In its rough crystalline form, a diamond will do none of these things; it requires proper fashioning and this is called "cut". In gemstones that have color, including colored diamonds, the purity, and beauty of that color is the primary determinant of quality.

Physical characteristics that make a colored stone valuable are color, clarity to a lesser extent (emeralds will always have a number of inclusions), cut, unusual optical phenomena within the stone such as color zoning (the uneven distribution of coloring within a gem) and asteria (star effects). Ancient Greeks, for example, greatly valued asteria gemstones, which they regarded as powerful love charms. Helen of Troy was supposed to have worn star-corundum.[15][failed verification]

Aside from the diamond, ruby, sapphire, and emerald, the pearl (not, strictly speaking, a gemstone) and opal[16] have also been considered[by whom?] to be precious. Up to the discoveries of bulk amethyst in Brazil in the 19th century, amethyst was considered a "precious stone" as well, going back to ancient Greece. Even in the last century certain stones such as aquamarine, peridot and cat's eye (cymophane) have been popular and hence been regarded as precious.

Today the gemstone trade no longer makes such a distinction.[17] Many gemstones are used in even the most expensive jewelry, depending on the brand-name of the designer, fashion trends, market supply, treatments, etc. Nevertheless, diamonds, rubies, sapphires, and emeralds still have a reputation that exceeds those of other gemstones.[18]

Rare or unusual gemstones, generally understood to include those gemstones which occur so infrequently in gem quality that they are scarcely known except to connoisseurs, include andalusite, axinite, cassiterite, clinohumite, painite and red beryl.[19]

Gemstone pricing and value are governed by factors and characteristics in the quality of the stone. These characteristics include clarity, rarity, freedom from defects, the beauty of the stone, as well as the demand for such stones. There are different pricing influencers for both colored gemstones, and for diamonds. The pricing on colored stones is determined by market supply-and-demand, but diamonds are more intricate.[20] Diamond value can change based on location, time, and on the evaluations of diamond vendors.[21][failed verification]

Proponents of energy medicine also value gemstones on the basis of alleged healing powers.[22]

A gemstone that has been rising in popularity is Cuprian Elbaite Tourmaline which is also called "Paraiba Tourmaline". It was first discovered in the late 1980s in Paraíba, Brazil and later in Mozambique and Nigeria.[23] It is famous for its glowing neon blue color. Paraiba Tourmaline has become one of the most popular gemstones in recent times thanks to its color and is considered to be one of the important gemstones after rubies, emeralds, and sapphires according to Gübelin Gemlab. Even though it is a tourmaline, Paraiba Tourmaline is one of the most expensive gemstones.[24]

Grading[edit]

There are a number of laboratories which grade and provide reports on gemstones.[17]

Gemological Institute of America (GIA), the main provider of education services and diamond grading reports

International Gemological Institute (IGI), independent laboratory for grading and evaluation of diamonds, jewelry, and colored stones

Hoge Raad Voor Diamant (HRD Antwerp), The Diamond High Council, Belgium is one of Europe's oldest laboratories; its main stakeholder is the Antwerp World Diamond Centre

American Gemological Society (AGS) is not as widely recognized nor as old as the GIA

American Gem Trade Laboratory which is part of the American Gem Trade Association (AGTA), a trade organization of jewelers and dealers of colored stones

American Gemological Laboratories (AGL), owned by Christopher P. Smith

European Gemological Laboratory (EGL), founded in 1974 by Guy Margel in Belgium

Gemmological Association of All Japan (GAAJ-ZENHOKYO), Zenhokyo, Japan, active in gemological research

The Gem and Jewelry Institute of Thailand (Public Organization) or GIT, Thailand's national institute for gemological research and gem testing, Bangkok[25]

Gemmology Institute of Southern Africa, Africa's premium gem laboratory

Asian Institute of Gemological Sciences (AIGS), the oldest gemological institute in South East Asia, involved in gemological education and gem testing

Swiss Gemmological Institute (SSEF), founded by Henry Hänni, focusing on colored gemstones and the identification of natural pearls

Gübelin Gem Lab, the traditional Swiss lab founded by Eduard Gübelin

Institute for Gems and Gold Research of VINAGEMS (Vietnam), founded by Van Long Pham[citation needed]

Each laboratory has its own methodology to evaluate gemstones. A stone can be called "pink" by one lab while another lab calls it "padparadscha". One lab can conclude a stone is untreated, while another lab might conclude that it is heat-treated.[17] To minimize such differences, seven of the most respected labs, AGTA-GTL (New York), CISGEM (Milano), GAAJ-ZENHOKYO (Tokyo), GIA (Carlsbad), GIT (Bangkok), Gübelin (Lucerne) and SSEF (Basel), have established the Laboratory Manual Harmonisation Committee (LMHC), for the standardization of wording reports, promotion of certain analytical methods and interpretation of results. Country of origin has sometimes been difficult to determine, due to the constant discovery of new source locations. Determining a "country of origin" is thus much more difficult than determining other aspects of a gem (such as cut, clarity, etc.).[26]

Gem dealers are aware of the differences between gem laboratories and will make use of the discrepancies to obtain the best possible certificate.[17]

Cutting and polishing[edit]

A diamond cutter in Amsterdam

A few gemstones are used as gems in the crystal or other forms in which they are found. Most, however, are cut and polished for usage as jewelry. The two main classifications are stones cut as smooth, dome-shaped stones called cabochons, and stones which are cut with a faceting machine by polishing small flat windows called facets at regular intervals at exact angles.

Stones which are opaque or semi-opaque such as opal, turquoise, variscite, etc. are commonly cut as cabochons. These gems are designed to show the stone's color or surface properties as in opal and star sapphires. Grinding wheels and polishing agents are used to grind, shape, and polish the smooth dome shape of the stones.[27]

Gems that are transparent are normally faceted, a method that shows the optical properties of the stone's interior to its best advantage by maximizing reflected light which is perceived by the viewer as sparkle. There are many commonly used shapes for faceted stones. The facets must be cut at the proper angles, which varies depending on the optical properties of the gem. If the angles are too steep or too shallow, the light will pass through and not be reflected back toward the viewer. The faceting machine is used to hold the stone onto a flat lap for cutting and polishing the flat facets.[28] Rarely, some cutters use special curved laps to cut and polish curved facets.

Colors[edit]

Nearly 300 variations of diamond color exhibited at the Aurora display at the Natural History Museum in London

A variety of semiprecious stones in a piece of jewellery

The color of any material is due to the nature of light itself. Daylight, often called white light, is all of the colors of the spectrum combined. When light strikes a material, most of the light is absorbed while a smaller amount of a particular frequency or wavelength is reflected. The part that is reflected reaches the eye as the perceived color. A ruby appears red because it absorbs all other colors of white light while reflecting red.

A material which is mostly the same can exhibit different colors. For example, ruby and sapphire have the same primary chemical composition (both are corundum) but exhibit different colors because of impurities. Even the same named gemstone can occur in many different colors: sapphires show different shades of blue and pink and "fancy sapphires" exhibit a whole range of other colors from yellow to orange-pink, the latter called "padparadscha sapphire".[29]

This difference in color is based on the atomic structure of the stone. Although the different stones formally have the same chemical composition and structure, they are not exactly the same. Every now and then an atom is replaced by a completely different atom, sometimes as few as one in a million atoms. These so-called impurities are sufficient to absorb certain colors and leave the other colors unaffected. For example, beryl, which is colorless in its pure mineral form, becomes emerald with chromium impurities. If manganese is added instead of chromium, beryl becomes pink morganite. With iron, it becomes aquamarine.Some gemstone treatments make use of the fact that these impurities can be "manipulated", thus changing the color of the gem.

Treatment[edit]

Gemstones are often treated to enhance the color or clarity of the stone.[30] In some cases, the treatment applied to the gemstone can also increase its durability. Even though natural gemstones can be transformed using the traditional method of cutting and polishing, other treatment options allow the stone's appearance to be enhanced.[31] Depending on the type and extent of treatment, they can affect the value of the stone. Some treatments are used widely because the resulting gem is stable, while others are not accepted most commonly because the gem color is unstable and may revert to the original tone.[32]

Early history[edit]

Before the innovation of modern-day tools, thousands of years ago, people were recorded to use a variety of techniques to treat and enhance gemstones. Some of the earliest methods of gemstone treatment date back to the Minoan Age, for example foiling, which is where metal foil is used to enhance a gemstone's colour.[33] Other methods recorded 2000 years ago in the book Natural History by Pliny the Elder include oiling and dyeing/staining.

Heat[edit]

Heat can either improve or spoil gemstone color or clarity. The heating process has been well known to gem miners and cutters for centuries, and in many stone types heating is a common practice. Most citrine is made by heating amethyst, and partial heating with a strong gradient results in "ametrine" – a stone partly amethyst and partly citrine. Aquamarine is often heated to remove yellow tones, or to change green colors into the more desirable blue, or enhance its existing blue color to a deeper blue.[32]

Nearly all tanzanite is heated at low temperatures to remove brown undertones and give a more desirable blue / purple color.[34] A considerable portion of all sapphire and ruby is treated with a variety of heat treatments to improve both color and clarity.

When jewelry containing diamonds is heated for repairs, the diamond should be protected with boric acid; otherwise, the diamond, which is pure carbon, could be burned on the surface or even burned completely up. When jewelry containing sapphires or rubies is heated, those stones should not be coated with boric acid (which can etch the surface) or any other substance. They do not have to be protected from burning, like a diamond (although the stones do need to be protected from heat stress fracture by immersing the part of the jewelry with stones in the water when metal parts are heated).

Radiation[edit]

Main article: Gemstone irradiation

The irradiation process is widely practiced in jewelry industry[35] and enabled the creation of gemstone colors that do not exist or are extremely rare in nature.[36] However, particularly when done in a nuclear reactor, the processes can make gemstones radioactive. Health risks related to the residual radioactivity of the treated gemstones have led to government regulations in many countries.[36][37]

Virtually all blue topaz, both the lighter and the darker blue shades such as "London" blue, has been irradiated to change the color from white to blue. Most green quartz (Oro Verde) are also irradiated to achieve the yellow-green color. Diamonds are mainly irradiated to become blue-green or green, although other colors are possible. When light-to-medium-yellow diamonds are treated with gamma rays they may become green; with a high-energy electron beam, blue.[38]

Waxing/oiling[edit]

Emeralds containing natural fissures are sometimes filled with wax or oil to disguise them. This wax or oil is also colored to make the emerald appear of better color as well as clarity. Turquoise is also commonly treated in a similar manner.

Fracture filling[edit]

The foreign material inside this fracture-filled emerald appears rainbow-colored under darkfield illumination.

Fracture filling has been in use with different gemstones such as diamonds, emeralds, and sapphires. In 2006 "glass-filled rubies" received publicity. Rubies over 10 carats (2 g) with large fractures were filled with lead glass, thus dramatically improving the appearance (of larger rubies in particular). Such treatments are fairly easy to detect.

Bleaching[edit]

Pearls are a gemstone that is commonly treated with hydrogen peroxide to remove unwanted colours

Another treatment method that is commonly used to treat gemstones is bleaching. This method uses a chemical in order to reduce the colour of the gem. After bleaching, a combination treatment can be done by dying the gemstone once the unwanted colours are removed. Hydrogen peroxide is the most commonly used product used to alter gemstones and have notably been used to treat jade and pearls. The treatment of bleaching can also be followed by impregnation, which allows the gemstone's durability to be increased.[31]

Synthetic and artificial gemstones[edit]

Synthetic gemstones are distinct from imitation or simulated gems.

Synthetic gems are physically, optically, and chemically identical to the natural stone, but are created in a laboratory.[39] Imitation or simulated stones are chemically different from the natural stone, but may appear quite similar to it; they can be more easily manufactured synthetic gemstones of a different mineral (spinel), glass, plastic, resins, or other compounds.

Examples of simulated or imitation stones include cubic zirconia, composed of zirconium oxide, synthetic moissanite, and uncolored, synthetic corundum or spinels; all of which are diamond simulants. The simulants imitate the look and color of the real stone but possess neither their chemical nor physical characteristics. In general, all are less hard than diamond. Moissanite actually has a higher refractive index than diamond, and when presented beside an equivalently sized and cut diamond will show more "fire".

Cultured, synthetic, or "lab-created" gemstones are not imitations: The bulk mineral and trace coloring elements are the same in both. For example, diamonds, rubies, sapphires, and emeralds have been manufactured in labs that possess chemical and physical characteristics identical to the naturally occurring variety. Synthetic (lab created) corundum, including ruby and sapphire, is very common and costs much less than the natural stones. Small synthetic diamonds have been manufactured in large quantities as industrial abrasives, although larger gem-quality synthetic diamonds are becoming available in multiple carats.[40]

Whether a gemstone is a natural stone or synthetic, the chemical, physical, and optical characteristics are the same: They are composed of the same mineral and are colored by the same trace materials, have the same hardness and density and strength, and show the same color spectrum, refractive index, and birefringence (if any). Lab-created stones tend to have a more vivid color since impurities common in natural stones are not present in the synthetic stone. Synthetics are made free of common naturally occurring impurities that reduce gem clarity or color unless intentionally added in order to provide a more drab, natural appearance, or to deceive an assayer.[citation needed] On the other hand, synthetics often show flaws not seen in natural stones, such as minute particles of corroded metal from lab trays used during synthesis.

Types[edit]

Some gemstones are more difficult to synthesize than others and not all stones are commercially viable to attempt to synthesize. These are the most common on the market currently.[41]

Synthetic corundum[edit]

Synthetic corundum includes ruby (red variation) and sapphire (other color variations), both of which are considered highly desired and valued.[41] Ruby was the first gemstone to be synthesized by Auguste Verneuil with his development of the flame-fusion process in 1902.[42] Synthetic corundum continues to be made typically by flame-fusion as it is most cost-effective, but can also be produced through flux growth and hydrothermal growth.[43]

Synthetic beryls[edit]

The most common synthesized beryl is emerald (green). Yellow, red and blue beryls are possible but much more rare. Synthetic emerald became possible with the development of the flux growth process and is produced in this way and well as hydrothermal growth.[44]

Synthetic quartz[edit]

Types of synthetic quartz include citrine, rose quartz, and amethyst. Natural occurring quartz is not rare is synthetically produced as it has practical application outside of aesthetic purposes. Quartz generates an electric current when under pressure and is used in watches, clocks, and oscillators.[45]

Synthetic spinel[edit]

Synthetic spinel was first produced by accident.[clarification needed] It can be created in any color making it popular to simulate various natural gemstones. It is created through flux growth and hydrothermal growth.[41]

Creation process[edit]

There are two main categories for creation of these minerals: melt or solution processes.[41]

Verneuil flame fusion process (melt process)[edit]

Verneuil furnace

The flame fusion process was the first process used which successfully created large quantities of synthetic gemstones to be sold on the market.[46] This remains the most cost effective and common method of creating corundums today.

The flame fusion process is completed in a Verneuil furnace. The furnace consists of an inverted blowpipe burner which produces an extremely hot oxyhydrogen flame, a powder dispenser, and a ceramic pedestal.[47] A chemical powder which corresponds to the desired gemstone is passed through this flames. This melts the ingredients which drop on to a plate and solidify into a crystal called a boule.[47] For corundum the flame must be 2000 °C. This process takes hours and yields a crystal with the same properties as its natural counterpart.

To produce corundum, a pure aluminium powder is used with different additives to achieve different colors.[47]

Chromic oxide for ruby

Iron and titanium oxide for blue sapphire

Nickel oxide for yellow sapphire

Nickel, chromium and iron for orange sapphire

Manganese for pink sapphire

Copper for blue-green sapphire

Cobalt for dark blue sapphire

Czochralski process (melt process)[edit]

In 1918 this process was developed by J. Czocharalski[47] and is also referred to as the "crystal pulling" method. In this process, the required gemstone materials are added to a crucible. A seed stone is placed into the melt in the crucible. As the gem begins to crystallize on the seed, the seed is pulled away and the gem continues to grow.[41] This is used for corundum but is currently the least popular method.[46]

Flux growth (solution process)[edit]

The flux growth process was the first process able to synthesize emerald.[44] Flux growth begins with a crucible which can withstand high heat; either graphite or platinum which is filled with a molten liquid referred to as flux.[48] The specific gem ingredients are added and dissolved in this fluid and recrystallize to form the desired gemstone.This is a longer process compared to the flame fusion process and can take two months up to a year depending on the desired final size.[49]

Hydrothermal growth (solution process)[edit]

The hydrothermal growth process attempts to imitate the natural growth process of minerals. The required gem materials are sealed in a container of water and placed under extreme pressure. The water is heated beyond its boiling point which allows normally insoluble materials to dissolve. As more material cannot be added once the container is sealed, in order to create a larger gem the process would begin with a "seed" stone from a previous batch which the new material will crystallize on. This process takes a few weeks to complete.

Characteristics[edit]

Synthetic gemstones share chemical and physical properties with natural gemstones, but there are some slight differences that can be used to discern synthetic from natural.[50] These differences are slight and often require microscopy as a tool to distinguish differences. Undetectable synthetics pose a threat to the market if they are able to be sold as rare natural gemstones. Because of this there are certain characteristic gemologists look for. Each crystal is characteristic to the environment and growth process under which it was created.

Visible banding in an apatite gemstone

Gemstones created from the flame-fusion process may have

small air bubbles which were trapped inside the boule during formation process

visible banding from formation of the boule

chatter marks which on the surface which appear crack like which are caused from damage during polishing of the gemstone

Gemstones created from flux melt process may have

small cavities which are filled with flux solution

inclusions in the gemstone from crucible used[51]

Gemstones created from hydrothermal growth may have

inclusions from container used[51]

History[edit]

Auguste Verneuil – creator of flame-fusion process 1902

Prior to development of synthesising processes the alternatives on the market to natural gemstones were imitations or fake. In 1837, the first successful synthesis of ruby occurred.[46] French chemist Marc Gaudin managed to produce small crystals of ruby from melting together potassium aluminium sulphate and potassium chromate through what would later be known as the flux melt process.[47] Following this, another French chemist Fremy was able to grow large quantities of small ruby crystals using a lead flux.[48]

A few years later an alternative to flux melt was developed which led to the introduction of what was labeled "reconstructed ruby" to the market. Reconstructed ruby was sold as a process which produced larger rubies from melting together bits of natural ruby.[49] In later attempts to recreate this process it was found to not be possible and is believed reconstructed rubies were most likely created using a multi-step method of melting of ruby powder.[47]

Auguste Verneuil, a student of Fremy, went on to develop flame-fusion as an alternative to the flux-melt method. He developed large furnaces which were able to produce large quantities of corundums more efficiently and shifted the gemstone market dramatically.[52] This process is still used today and the furnaces have not changed much from the original design.[53] World production of corundum using this method reaches 1000 million carats a year.

List of rare gemstones[edit]

Painite was discovered in 1956 in Ohngaing in Myanmar. The mineral was named in honor of the British gemologist Arthur Charles Davy Pain. At one point it was considered the rarest mineral on Earth.[54]

Tanzanite was discovered in 1967 in Northern Tanzania. With its supply possibly declining in the next 30 years, this gemstone is considered to be more rare than a diamond. This type of gemstone receives its vibrant blue from being heated.[55]

Hibonite was discovered in 1956 in Madagascar. It was named after the discoverer, French geologist Paul Hibon. Gem quality hibonite has been found only in Myanmar.[56]

Red Beryl - discovered in 1940

Red beryl or bixbite was discovered in an area near Beaver, Utah in 1904 and named after the American mineralogist Maynard Bixby.

Jeremejevite was discovered in 1883 in Russia and named after its discoverer, Pawel Wladimirowich Jeremejew (1830–1899).

Chambersite was discovered in 1957 in Chambers County, Texas, US, and named after the deposit's location.

Taaffeite was discovered in 1945. It was named after the discoverer, the Irish gemologist Count Edward Charles Richard Taaffe.

Musgravite was discovered in 1967 in the Musgrave Mountains in South Australia and named for the location.

Black Opal – the rarest type of opal

Black opal is directly mined in New South Wales, Australia, making it the rarest type of opal. Having a darker composition, this gemstone can be in a variety of colours.[55]

Grandidierite was discovered by Antoine François Alfred Lacroix (1863–1948) in 1902 in Tuléar Province, Madagascar. It was named in honor of the French naturalist and explorer Alfred Grandidier (1836–1912).

Poudretteite was discovered in 1965 at the Poudrette Quarry in Canada and named after the quarry's owners and operators, the Poudrette family.

Serendibite was discovered in Sri Lanka by Sunil Palitha Gunasekera in 1902 and named after Serendib, the old Arabic name for Sri Lanka.

Zektzerite was discovered by Bart Cannon in 1968 on Kangaroo Ridge near Washington Pass in Okanogan County, Washington, USA. The mineral was named in honor of mathematician and geologist Jack Zektzer, who presented the material for study in 1976.

In popular culture[edit]

French singer-songwriter Nolwenn Leroy was inspired by the gemstones for her 2017 album Gemme (meaning gemstone in French) and the single of the same name.[57]

Land of the Lustrous is an anime and manga series whose main characters are depicted as humanoid gemstones.

Steven Universe is an American animated television series whose main characters are magical gemstones who project themselves as feminine humanoids.

See also[edit]

Assembled gem

Gemology

List of gemstones by species

List of individual gemstones

List of diamonds

List of emeralds by size

List of sapphires by size

Luminous gemstones

References[edit]

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^ Bauer, Max (1968). Precious Stones. Dover Publications. p. 2. ISBN 9780486219103.

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^ Read, Peter G. (2005). Gemmology. Butterworth-Heinemann. p. 13. ISBN 978-0-7506-6449-3.

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^ "A complete guide to Gemstones". Jewellery Monthly. April 2, 2015. Archived from the original on August 28, 2017.

^ "Pricing of Colored Gemstones | Joseph Menzie Inc". Archived from the original on October 27, 2021. Retrieved October 27, 2021.

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Katz, Michael (2005). Gemstone Energy Medicine: Healing Body, Mind and Spirit. Natural Healing Press. ISBN 9780924700248. Retrieved April 6, 2020.

^ "Geographic Origin Determination of Paraíba Tourmaline". Archived from the original on April 9, 2022. Retrieved March 17, 2022.

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^ "The Gem and Jewelry Institute of Thailand (Public Organization)". Bangkok Post.

^ "Rapaport report of ICA Gemstone Conference in Dubai". Diamonds.net. May 16, 2007. Archived from the original on July 26, 2011. Retrieved July 30, 2010.

^ Kraus, Pansy D. (2007). Introduction to Lapidary. Krause Publications. ISBN 9780801972669.

^ Vargas, Glenn; Vargas, Martha (2002). Faceting For Amateurs. G. & M. Vargas. ISBN 9780917646096.

^ "Padparadscha Sapphires: 10 Tips On Judging The Rare Gem". The Natural Sapphire Company Blog. April 6, 2015. Archived from the original on January 19, 2018. Retrieved January 19, 2018.

^ Nassau, Kurt (1984). Gemstone enhancement: heat, irradiation, impregnation, dyeing, and other treatments which alter the appearance of gemstones, and the detection of such treatments. London u.a: Butterworths. ISBN 978-0-408-01447-2.

^ a b "An Introduction to Gem Treatments". www.gia.edu. Archived from the original on April 6, 2023. Retrieved March 31, 2023.

^ a b Nassau, Kurt (1994). Gemstone Enhancement: History, Science and State of the Art (2nd ed.). Oxford: Butterworth Heinemann. ISBN 9780750617970. OCLC 28889342.

^ Nassau, Kurt (1984). "The Early History of Gemstone Treatments" (PDF). Archived (PDF) from the original on January 2, 2023. Retrieved March 31, 2023.

^ "Tanzanite heating – the science". Archived from the original on 20 June 2016.

^ Omi, Nelson M.; Rela, Paulo R. (2007). Gemstone Dedicated Gamma Irradiator Development: Proceedings of the INAC 2007 International Nuclear Atlantic Conference (PDF). Associação Brasileira de Energia Nuclear. p. 1. ISBN 978-85-99141-02-1. Archived from the original (PDF) on October 21, 2022. Retrieved October 21, 2022.

^ a b Hurlbut, Cornelius S.; Kammerling, Robert C. (1991). Gemology (PDF). Wiley-Interscience. p. 170. ISBN 0-471-52667-3. Archived (PDF) from the original on November 4, 2022. Retrieved November 4, 2022 – via LibreTexts.

^ Nuclear Regulatory Commission (April 2019). "Backgrounder on Irradiated Gemstones". The U.S. Nuclear Regulatory Commission. Archived from the original on September 1, 2022. Retrieved November 12, 2022.  This article incorporates public domain material from websites or documents of the United States Government.

^ Rossman, George R. (Summer 1981). "Color in Gems: The New Technologies" (PDF). Gems & Gemology. Gemological Institute of America. 17 (2): 70. doi:10.5741/GEMS.17.2.60. ISSN 0016-626X. Archived from the original (PDF) on November 12, 2022.

^ Jewelers' circular-keystone: JCK. Chilton Company. 1994.[full citation needed]

^ "New process promises bigger, better diamond crystals". Carnegie Institution for Science. Archived from the original on December 1, 2010. Retrieved January 7, 2011.

^ a b c d e Weldon, R. "An Introduction to Synthetic Gem Materials" (PDF). Archived (PDF) from the original on April 15, 2023. Retrieved April 14, 2023.

^ Shigley, James (2000). "Treated and synthetic gem materials". Current Science. 79 (11): 1566–1571. JSTOR 24104849.

^ Elwell, Dennis (1981). Nassau, Kurt (ed.). "Synthetic Gemstones". Science. 211 (4487): 1156. doi:10.1126/science.211.4487.1156.a. ISSN 0036-8075. JSTOR 1685235. PMID 17755153. S2CID 239860410. Archived from the original on April 15, 2023. Retrieved April 15, 2023.

^ a b Lefever, R (1982). "Synthetic emerald". pubs.geoscienceworld.org. Retrieved March 15, 2023.

^ Hervey, P. R.; Foise, J. W. (February 1, 2001). "Synthetic quartz crystal — A review". Mining, Metallurgy & Exploration. 18 (1): 1–4. doi:10.1007/BF03402862. ISSN 2524-3470. S2CID 140031745.

^ a b c Scheel, Hans J (April 1, 2000). "Historical aspects of crystal growth technology". Journal of Crystal Growth. 211 (1): 1–12. Bibcode:2000JCrGr.211....1S. doi:10.1016/S0022-0248(99)00780-0. ISSN 0022-0248. Archived from the original on April 15, 2023. Retrieved April 15, 2023.

^ a b c d e f Read, Peter G. (1999). Gemmology. Butterworth-Heinemann. ISBN 0-7506-4411-7. OCLC 807757024.

^ a b Scheel, Hans (2003). Crystal Growth Technology. John Wiley & Sons. ISBN 9780470871683.

^ a b Arem, Joel. "Understanding Gem Synthetics, Treatments, And Imitations, Part 4: Synthetic Gemstone Guide". International Gem Society. Archived from the original on March 22, 2023. Retrieved March 30, 2023.

^ Jayaraman, A (December 28, 2023). "A brief overview of gem materials: Natural and synthetic". Current Science. 79 (11): 1555–1565. JSTOR 24104848. Archived from the original on April 15, 2023.

^ a b Li, Zhaolin (December 1, 2001). "Study on inclusions in natural and synthetic gems". Chinese Journal of Geochemistry. 20 (4): 324–332. doi:10.1007/BF03166857. ISSN 1993-0364. S2CID 129031255.

^ Nassau, Kurt (1990). "Synthetic Gem Materials in the 1980s" (PDF). Gems & Gemology. 26 (1): 50–63. doi:10.5741/GEMS.26.1.50. Archived (PDF) from the original on November 1, 2021. Retrieved April 15, 2023.

^ Harris, Daniel C. (September 26, 2003). Tustison, Randal W. (ed.). "A peek into the history of sapphire crystal growth". Window and Dome Technologies VIII. SPIE. 5078: 1–11. Bibcode:2003SPIE.5078....1H. doi:10.1117/12.501428. S2CID 109528895.

^ Hansen 2022, p. 206.

^ a b "10 Gems Rarer and More Valuable Than Diamonds". The Spruce Crafts. Archived from the original on March 31, 2023. Retrieved March 31, 2023.

^ Hainschwang, Thomas; Notari, Franck; Massi, Laurent; Armbruster, Thomas; Rondeau, Benjamin; Fritsch, Emmanuel; Nagashima, Mariko (Summer 2010). "Hibonite: A New Gem Mineral" (PDF). Gems & Gemology. 46 (2): 135–138. doi:10.5741/GEMS.46.2.135. Archived (PDF) from the original on December 13, 2017.

^ (in French) "VIDÉO - Nolwenn Leroy lumineuse et enceinte dans le clip de Gemme". RTL. 19 July 2017.

External links[edit]

Quotations related to Gemstone at Wikiquote

Media related to Gemstones at Wikimedia Commons

The dictionary definition of gemstones at Wiktionary

Gemstone travel guide from Wikivoyage

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List of Gemstones: Precious and Semi-Precious Stones - Gem Society

of Gemstones: Precious and Semi-Precious Stones - Gem SocietyMEMBERSHIPSearchLearning CenterGemologyScience, tools, identification, treatment, valuation & grading of gemsJewelry & LapidaryGemstone jewelry settings, metals, tools, cutting & faceting stonesGemstone EncyclopediaList of all gemstones from A-Z with in-depth information for eachGem Photo GalleryThousands of gem photos searchable by various properties.Diamond Buying AdviceEverything you need to know about buying your perfect diamondBirthstonesLearn more about these popular gemstones, their meaning & about buying birthstone jewelryGem PricingGemstone Price GuidesPrice guidance on over 70 types of gemstonesExpert Buying GuidesIn-depth guides to quality factors of the 40 most popular gemstonesCoursesOverviewMini CoursesProfessional Gemologist CertificationDiamond Specialist CertificationCommunityGem BusinessesView AllAppraisalsAuctionsGem CuttingGem TreatingGemological LaboratoriesGemology Supplies & EquipmentGemstonesInformational ResourcesJewelryLapidary Supplies & EquipmentRough Gems & Mineral SpecimensAboutAbout IGSAdvertiseContact UsFAQSupportPressLearning CenterGemstone EncyclopediaDetailed information for any gemstone you are interested in.0 GemstoneActinoliteActinolite is a member of a series that contains varying amounts of ir...Gem ProfileAdamiteAlthough adamite occurs in many localities, it's very rarely cut as a ...Gem ProfileAgateAgate is a variety of chalcedony that exists in many colors and is oft...Gem ProfileBuying GuideAlbiteAlbite, usually colorless but sometimes yellow, pink, gray or reddish....Gem ProfileAlexandrite“Emerald by day, ruby by night,” alexandrite is well known for display...Gem ProfileBuying GuideAlgodoniteBright, silvery metallic cabochons of algodonite and domeykite are att...Gem ProfileAlmandine GarnetAlmandine is perhaps the most common garnet species. Forming series wi...Gem ProfileBuying GuideAmazoniteA green to blue-green variety of microcline, amazonite makes a wonderf...Gem ProfileAmberAmber is the hardened resin of ancient pine trees. This organic substa...Gem ProfileBuying GuideAmblygoniteAmblygonite gems are usually pale straw yellow. Although they are too ...Gem ProfileAmethystAmethyst is crystalline quartz in colors ranging from pale lilac to de...Gem ProfileBuying GuideAmetrineAmetrine is a variety of quartz that displays bands of both amethyst p...Gem ProfileBuying GuideAmmoliteAmmolite is a rare, iridescent, gem-quality material cut from the foss...Gem ProfileBuying GuideAnalcimeLarge colorless crystals of Analcime are a great rarity although small...Gem ProfileAnataseAnatase occurs in many beautiful colors, such as deep indigo and amber...Gem ProfileAndalusiteStrongly pleochroic, andalusite can show shades of green, brown, and r...Gem ProfileAndesineThese feldspars are rarely encountered in gem form. Andesine's occurre...Gem ProfileAndraditeAndradite is one of the most sought after garnet species. Although mor...Gem ProfileBuying GuideAnglesiteAlthough anglesites with pale colors can show great dispersion and bri...Gem ProfileAnhydrite (Angelite)Rare and difficult to cut, anhydrite is seldom faceted. However, this ...Gem ProfileAnorthiteThe rarest plagioclase feldspar, anorthite is very rarely faceted.Gem ProfileApatiteAlthough too brittle for most jewelry use, properly cut apatite gems a...Gem ProfileApophylliteAlthough not suitable for jewelry, apophyllite is a popular collector'...Gem ProfileAquamarineNamed after the color of sea water, aquamarine is the blue to blue-gre...Gem ProfileBuying GuideAragoniteAragonite is more commonly found as a constituent of pearl and shell n...Gem ProfileArtisanal GlassGlass has been used in jewelry for thousands of years. By itself, glas...Gem ProfileAugeliteSoft and brittle, rare augelites are difficult to cut and unsuitable f...Gem ProfileAxiniteWhen faceted, the members of the axinite mineral group are usually int...Gem ProfileAzuriteCollectors prize deep blue azurite crystals, but faceted gems are extr...Gem ProfileBariteMassive white barite (also called known as baryte) looks like marble a...Gem ProfileBayldoniteBayldonite is a nondescript greenish material that has been cut into c...Gem ProfileBenitoiteWith dispersion higher than diamond and sapphire-blue body color, beni...Gem ProfileBerylThe beryls are among the most popular, and also the most expensive, of...Gem ProfileBerylloniteDifficult to facet and typically colorless, beryllonite is a rare coll...Gem ProfileBismutotantaliteExtremely rare as a cut gem, even in very complete collections. Many o...Gem ProfileBlack DiamondBlack is a color that can say a lot. Wearing black diamond jewelry com...Gem ProfileBloodstoneAlso known as heliotrope, bloodstone is the traditional March birthsto...Gem ProfileBlue DiamondBlue diamonds may be rare, but they have gained a big reputation over ...Gem ProfileBoleiteCut boleite is strictly for collectors, since it is soft and very rare...Gem ProfileBoraciteWith light blue and green colors, no cleavage, and high hardness, bora...Gem ProfileBorniteBornite is suitable only for cabochons. The bronzy color rapidly tarni...Gem ProfileBrazilianiteBrazilianite's lovely green to yellow colors make it a must for gem co...Gem ProfileBreithauptiteBreithauptite is a curiosity cut for collectors, although it could be ...Gem ProfileBrookiteBrookite usually occurs in very dark colors, transparent only in small...Gem ProfileBrown DiamondThe most common of all fancy colors that can be expressed by diamonds ...Gem ProfileBruciteBrucites are extremely difficult to cut. Although too soft for jewelry...Gem ProfileBustamitePale pink and brownish red bustamite can make a very attractive facete...Gem ProfileBytowniteAlthough bytownite occurs throughout the world, this feldspar variety ...Gem ProfileCalcareous ConcretionsSeveral species of marine mollusks produce stony growths called calcar...Gem ProfileBuying GuideCalciteCalcite is common and abundant throughout the world. The material has ...Gem ProfileCanasiteThe material usually seen on the market as “canasite” is purplish in c...Gem ProfileCancriniteCancrinite is one of the most attractive of all opaque or translucent ...Gem ProfileCarnelianThe best-known and generally least expensive variety of chalcedony is ...Gem ProfileCassiteriteCassiterite is a durable gemstone with tremendous dispersive fire, esp...Gem ProfileCatapleiiteThe only reported cut catapleiite is from Mte. Ste. Hilaire, Quebec, C...Gem ProfileCelestiteSoft, fragile, and hard to cut, celestite or celestine is seldom seen ...Gem ProfileCeruleiteA little-known gem material of truly exquisite color, sky-blue cerulei...Gem ProfileCerussiteAs beautiful as a diamond, a faceted cerussite actually has higher dis...Gem ProfileChabaziteAlthough faceting chabazite isn't too difficult, it's too soft for jew...Gem ProfileChalcedonyTechnically, chalcedony (kal SED' uh nee) is any form of microcrystall...Gem ProfileBuying GuideChambersiteChambersite is an exceedingly rare mineral. Although it has properties...Gem ProfileChameleon DiamondProfessionals will tell you never to trust a trade name used to descri...Gem ProfileCharoiteWith light to medium dark purple colors and swirling patterns, charoit...Gem ProfileChicken-Blood StoneOne of the most prized ornamental materials in China, chicken-blood st...Gem ProfileChildreniteCut childrenite is a great rarity, and all gems are small. Cut eosphor...Gem ProfileChioliteChiolite makes a challenging gem. It's difficult to cut, extremely rar...Gem ProfileChromiteChromite is shiny and black, and makes a curious-looking cabochon with...Gem ProfileChrysoberylAlthough many gems show a cat’s eye effect, when the term “cat’s eye” ...Gem ProfileBuying GuideChrysocollaPure blue chrysocolla is extremely soft but interesting to gem collect...Gem ProfileChrysocolla ChalcedonyMarketed as "Gem Silica" this relatively rare, blue to blue-green, opa...Gem ProfileChrysopraseChrysoprase is apple-green chalcedony that derives its color from nick...Gem ProfileBuying GuideCinnabarMagnificent red cinnabar is extremely soft and fragile, so faceted mat...Gem ProfileCitrineCitrine is the yellow to red-orange variety of crystalline quartz. Cle...Gem ProfileBuying GuideClinochloreClinochlore is a family of minerals in the chlorite group. To date, on...Gem ProfileCobaltiteCobaltite cabochons can have a lovely metallic luster. However, this g...Gem ProfileColemaniteColemanite is an abundant mineral, and transparent material isn’t rare...Gem ProfileColor Change GarnetAny stone that changes color under different types of light is a rare ...Gem ProfileBuying GuideColor Change SapphireColor change sapphires are those that change color between light sourc...Gem ProfileCoralCoral is the external skeleton of a tiny, plant-like marine animal cal...Gem ProfileBuying GuideCordieriteThe crystal structure of cordierite has many similarities to that of b...Gem ProfileBuying GuideCorundumNext to diamond, corundum is the hardest mineral known and is very com...Gem ProfileCovelliteAlthough covellite has attractive blue colors and shows iridescence, t...Gem ProfileCreediteProbably fewer than a dozen creedite gems have ever been faceted. This...Gem ProfileCrocoiteLovely saffron-colored crocoite is quite a rare mineral. Although too ...Gem ProfileCryoliteTypically colorless with a “sleepy” look, cryolite is rarely found in ...Gem ProfileCupriteOne of the rarest of all facetable gems, cut cuprites can show magnifi...Gem ProfileDanburiteA very durable gemstone, danburite is an excellent choice for jewelry ...Gem ProfileDatolitePolished and sliced datolite nodules can show off very attractive colo...Gem ProfileDemantoid GarnetOne of the rarest garnet varieties, demantoid can have a green color t...Gem ProfileBuying GuideDiamondDiamond is the most romanticized and heavily marketed of all gemstones...Gem ProfileBuying GuideDiasporeDiaspore is hard enough to make a durable jewelry stone, but the typic...Gem ProfileDickinsoniteThis mineral is seldom even mentioned in the gem literature because it...Gem ProfileDiopsideViolane has been used for beads and inlay—transparent material is alwa...Gem ProfileDioptaseDioptase has a beautiful, emerald-like green color. Although this mine...Gem ProfileDolomiteAlthough transparent dolomite crystals are fairly abundant and popular...Gem ProfileDumortieriteDumortierite is a beautiful and very hard material, eminently suitable...Gem ProfileEkaniteA relative newcomer to the world of gemstones, ekanite is rare and usu...Gem ProfileEmeraldEmerald has been synonymous with the color green since ancient times. ...Gem ProfileBuying GuideEnstatiteMost gem enstatites have indices in the range 1.663-1.673. The brown a...Gem ProfileEosphoriteFaceted eosphorites in pale colors are quite attractive and easy to cu...Gem ProfileEpidoteThe epidote mineral supergroup contains many related species of intere...Gem ProfileEttringiteEttringite is not generally facetable. Any cut stone would be consider...Gem ProfileEuclaseAlthough hard enough to be worn safely in jewelry, euclase in beautifu...Gem ProfileEudialyteAlthough lapidaries can cut cabochons and decorative objects from mass...Gem ProfileEuxeniteEuxenite is seldom seen in collections. Most collectors would not rega...Gem ProfileFeldsparFeldspars are the most common minerals at the Earth's surface. In fact...Gem ProfileBuying GuideFergusoniteThis mineral is not abundant and is known from various localities. Cab...Gem ProfileFluoriteAlthough too fragile for most jewelry use, fluorites are often faceted...Gem ProfileFreshwater PearlLike their marine cousins, many freshwater mollusks can produce pearls...Gem ProfileBuying GuideFriedeliteFriedelite is not abundant, and gem-quality material is rarely seen ev...Gem ProfileGadoliniteThis is not a terribly attractive gemstone, but faceted gems would be ...Gem ProfileGahnospinelGahnospinel is a solid-state solution between spinel and gahnite.Gem ProfileGarnetAlthough commonly associated with the color red, garnets can be found ...Gem ProfileBuying GuideGaylussiteThis mineral is very hard to cut because of extreme softness and cleav...Gem ProfileGrandidieriteA rather rare mineral, lovely blue-green grandidierite is seldom seen ...Gem ProfileGray DiamondDiamonds with a pure gray hue are a rare treasure indeed. More often, ...Gem ProfileGreen DiamondGreen diamonds are the oddballs of the fancy colored diamond varieties...Gem ProfileGrossular GarnetGrossular garnets come in almost every color, even colorless, except b...Gem ProfileBuying GuideGypsumGypsum is one of the most abundant minerals, but gem-quality crystals ...Gem ProfileHambergiteAlthough hard enough for jewelry use, rare hambergite is a gem for col...Gem ProfileHaüyneOne of the major mineral constituents of lapis lazuli, haüyne is rarel...Gem ProfileHeliodorHeliodor is a member of the beryl family. This stone is known for its ...Gem ProfileHematiteHematite has a long history of use as a pigment. As a gemstone, this m...Gem ProfileHemimorphiteMassive hemimorphite can have a very delicate, blue color. However, it...Gem ProfileHerderiteHerderite is a rare collector's gem, especially in larger sizes. Altho...Gem ProfileHessoniteAlso known as the “cinnamon stone,” hessonite is the yellow-orange to ...Gem ProfileBuying GuideHodgkinsoniteHodgkinsonite is one of the rarest of all collector gems. Cut stones a...Gem ProfileHoltiteThis mineral was first noted in 1937 but was not described in detail u...Gem ProfileHowliteHowlite is always opaque in nodules; it is an abundant material and ea...Gem ProfileHuebnerite (Hübnerite)It should not be difficult to find numerous small faceted huebnerites ...Gem ProfileHumiteClinohumites and chondrodites can make beautiful gemstones with rich c...Gem ProfileHureauliteHureaulite can show rich and lively pink, rose, and orange colors. How...Gem ProfileHurlbutiteHurlbutite is an extremely rare mineral. Minute, colorless faceted sto...Gem ProfileHydrogrossular GarnetHydrogrossular differs from the other garnets in that it is never tran...Gem ProfileBuying GuideHyperitdiabasHyperitdiabas is one of the most outstanding minerals I have encounter...Gem ProfileIdocrase (Vesuvianite)Idocrase is one of the lesser known and more beautiful collector gems....Gem ProfileInderiteInderite is very soft and difficult to cut, and only a few stones have...Gem ProfileIoliteThis stone, which represents one of the few relatively available and a...Gem ProfileBuying GuideJadeiteOne of two distinct minerals commonly known as jade, jadeite is the ra...Gem ProfileBuying GuideJasperJasper is an opaque, solid or patterned variety of cryptocrystalline q...Gem ProfileJeremejeviteJeremejevite would make a durable and attractive jewelry stone, but th...Gem ProfileJetHistorically a popular black gem, jet has declined in popularity in mo...Gem ProfileKornerupineStar kornerupine also has been found (Mogok, Myanmar) but is very rare...Gem ProfileKurnakoviteKurnakovite is difficult to cut, inadvisable to wear, and usually colo...Gem ProfileKyaniteKyanite’s physical properties make it very difficult to facet. However...Gem ProfileKämmereriteA beautiful but rare mineral, kämmererite is extraordinarily difficult...Gem ProfileLabradoriteAn overview on Labradorite Jewelry and Gemstones. Covers details and e...Gem ProfileBuying GuideLangbeiniteThis material is nondescript and is cut solely as a curiosity. The gem...Gem ProfileLapis LazuliLapis lazuli has been used since ancient times and remains popular tod...Gem ProfileBuying GuideLaserblueLaserblue is a rare, synthetic glass. It's hard for glass but easy to ...Gem ProfileLawsoniteLawsonite is extremely rare as a faceted stone, seldom reported and ge...Gem ProfileLazuliteLazulite makes a magnificent, deep blue gemstone. Although the mineral...Gem ProfileLegranditeToo soft for jewelry use, legrandite is a popular collector’s mineral ...Gem ProfileLepidoliteReddish granular or massive lepidolite is usually slabbed for ornament...Gem ProfileLeuciteAlthough abundant in various lava rocks, leucite is extremely rare in ...Gem ProfileLinariteThe blue color of linarite is magnificent, and it is a pity that large...Gem ProfileLudlamiteLudlamite has a lovely green color, but cut stones are extremely rare....Gem ProfileMagnesiteTransparent, gem-quality magnesite is rare and beautiful, with colors ...Gem ProfileMalachiteMalachite is a beautiful decorative stone. Its rich, patterned colorat...Gem ProfileMalaia Garnet (Malaya Garnet)Malaia or malaya garnets are typically light to dark, slightly pinkish...Gem ProfileBuying GuideMali GarnetOne of the rarer varieties in the garnet group, Mali garnet is a blend...Gem ProfileBuying GuideMandarin GarnetWhile the colors of spessartite garnet gemstones cover a wide range of...Gem ProfileBuying GuideManganotantaliteManganotantalite makes a spectacular red brown gem that is a very rare...Gem ProfileMarcasiteMarcasite has a long history of use as a decorative and jewelry materi...Gem ProfileMeliphaniteMeliphanite is an extremely rare gemstone, and perhaps fewer than 5-10...Gem ProfileMelliteMellite is a rare and unusual organic gemstone. Although soft and frag...Gem ProfileMicroclineMicrocline is a variety of feldspar. The only microcline you are likel...Gem ProfileMicroliteRanging in color from pale yellow to brown, reddish, and green, microl...Gem ProfileMilariteVery rare milarite crystals can occur in green and yellow colors. Tran...Gem ProfileMilleriteMillerite has a rich, attractive yellow color. Massive millerites can ...Gem ProfileMimetiteTransparent mimetite crystals are extremely rare, and very few have ev...Gem ProfileMoldaviteAn olive to bottle-green natural glass, moldavite is a rare material p...Gem ProfileMonaziteMonazite may be partially metamict, with N=1.79. Stones can be an attr...Gem ProfileMoonstoneFound all over the world, moonstone is prized for its blue to white ad...Gem ProfileBuying GuideMordeniteCompact, fibrous material is cabbed because the fibers provide a chato...Gem ProfileMorganiteA member of the beryl family, morganite shows a range of pink colors d...Gem ProfileBuying GuideNambuliteThe color of Namibian nambulite is a striking orange-red, very intense...Gem ProfileNatrolite, Mesolite, ScoleciteAll three minerals are fibrous or elongated zeolite minerals. Faceted ...Gem ProfileNatural GlassGlass comes in several natural forms. All are used in jewelry.Gem ProfileNephelineA variety called elaeolite is red, green, brown, or gray, massive or i...Gem ProfileNephriteNephrite is one of the two distinct minerals commonly known as jade. W...Gem ProfileBuying GuideNeptuniteAn overview on Neptunite Jewelry and Gemstones. Covers details and ess...Gem ProfileNiccolite (Nickeline)Niccolite’s delicate peachy red color and metallic luster looks beauti...Gem ProfileObsidianObsidian is the most common form of natural glass and occurs in many a...Gem ProfileOligoclaseOligoclase gems are feldspars that are part of a solid state series be...Gem ProfileOnyxFor millennia, artisans have carved intricate cameos from black-and-wh...Gem ProfileOpal StoneOpals are in a class by themselves. As a species, opal is so unique it...Gem ProfileBuying GuideOrange DiamondQuite a few diamonds on the market display orange as part of a multi-h...Gem ProfileOregon SunstoneWhile feldspar sunstones from sources around the world have been used ...Gem ProfileBuying GuideOrthoclaseOrthoclase is best known for moonstone. It is occasionally a transpare...Gem ProfilePadparadscha SapphirePadparadscha sapphires show a blend of orange and pink colors, one of ...Gem ProfileBuying GuidePainiteUntil 2001, only three painite crystals were known to exist. Since the...Gem ProfilePalygorskiteAlthough marketed as “angel skin opal,” “rock wood,” and “mountain lea...Gem ProfilePapagoiteCerulean blue papagoite crystals are too small for faceting. However, ...Gem ProfileParaíba TourmalineDiscovered in 1989, paraíba tourmalines are among the world’s most pri...Gem ProfileBuying GuidePargasiteThe amphibole group is very large and extremely complex and contains n...Gem ProfileParisiteMore well-known as rare inclusions in emeralds, parisite crystals are ...Gem ProfilePearlPearls are the only gems found within living creatures, both salt and ...Gem ProfileBuying GuidePectolite (Larimar)Fibrous pectolite has long been a curiosity for gem collectors. Compac...Gem ProfilePentlanditePentlandite resembles other yellowish metallic minerals and is cut by ...Gem ProfilePericlasePericlase has been synthesized in large masses in the laboratory, but ...Gem ProfilePeridotThe modern August birthstone, peridot has been prized as a jewelry sto...Gem ProfileBuying GuidePeristeritePeristerite is primarily oligoclase with a complex mixture of feldspar...Gem ProfileBuying GuidePerthitePerthite is a blend of microcline, albite and oligoclase. It is usuall...Gem ProfilePetaliteGem-quality, colorless, facetable petalite is rare and desirable to co...Gem ProfilePhenakiteRare phenakite is a very hard gem material suitable for jewelry. Usual...Gem ProfilePhosgeniteRare phosgenite typically shows pale colors. This material is difficul...Gem ProfilePhosphophylliteRenowned for its delicate blue-green shades, phosphophyllite’s beauty ...Gem ProfilePink DiamondPink diamond is one of nature’s rarest beauties. Often found in small ...Gem ProfilePolluciteColorless pollucites lack fire when cut and are usually small. However...Gem ProfilePowelliteAn overview on Powellite Jewelry and Gems. Covers details and essentia...Gem ProfilePrehnitePrehnite is popular as a cabochon material among hobbyists because of ...Gem ProfileProsopiteProsopite is usually a nondescript mineral with no gem significance. H...Gem ProfileProteusA few almandine/pyrope garnets from the US will change with treatment ...Gem ProfileBuying GuideProustiteProustite crystals have magnificent red colors and good brilliance. Al...Gem ProfilePumpellyiteThe gem variety of pumpellyite, chlorastrolite, is best known from the...Gem ProfilePurple DiamondPurple is a powerful color that historically has been linked with wisd...Gem ProfilePurpuritePurpurite is too soft for jewelry wear and never transparent. Neverthe...Gem ProfilePyrargyriteDeep red pyrargyrite occurs in a number of localities in well-formed b...Gem ProfilePyritePyrite is more commonly known as fool’s gold and is familiar to nearly...Gem ProfilePyrope GarnetPyrope always occurs in series with other garnet species. Common, dark...Gem ProfileBuying GuidePyrophyllitePyrophyllite resembles talc in many ways and is indistinguishable by e...Gem ProfilePyroxmangitePyroxmangite grains are rare, seldom clean enough to facet, and diffic...Gem ProfilePyrrhotiteAn overview on Pyrrhotite Jewelry and Gemstones. Covers details and es...Gem ProfileQuartzAn overview on Quartz Jewelry and Gemstones. Covers details and essent...Gem ProfileBuying GuideQuartziteQuartzite is a rock made up of tightly packed quartz grains. Sometimes...Gem ProfileRealgarAlthough this common arsenic sulfide mineral occurs worldwide, cut gem...Gem ProfileRed BerylOriginally known as bixbite, red beryl is one of the rarest, most desi...Gem ProfileRed DiamondThe discovery of any fancy-colored diamond is an exceedingly rare and ...Gem ProfileRhodiziteRhodizite is tough enough to make an excellent jewelry stone. However,...Gem ProfileRhodochrositeBeautiful rose red to pink rhodochrosite crystals are popular with min...Gem ProfileRhodolite GarnetRhodolites are purplish red garnets, a blend between almandine and pyr...Gem ProfileBuying GuideRhodoniteRanging in color from pink to a fine rose red, rhodonite is a popular ...Gem ProfileRose QuartzA popular variety of colored quartz, rose quartz makes a durable jewel...Gem ProfileBuying GuideRubelliteRubellites are tourmalines with reasonably saturated dark pink to red ...Gem ProfileBuying GuideRubyOne of the most popular traditional jewelry stones, ruby is exceptiona...Gem ProfileBuying GuideRutileThough perhaps best known as inclusions within other gems, rutile crys...Gem ProfileSaltwater PearlAlthough pearls are one of humanity’s most ancient gems, natural under...Gem ProfileBuying GuideSamarskiteSamarskite is a very heavy material from which lustrous black to brown...Gem ProfileSanidineSanidine is a mineral of volcanic rocks, rarely considered a gem. Whil...Gem ProfileSapphireFew gems have held our attention over millennia as well as sapphire. T...Gem ProfileBuying GuideSapphirineSapphirines are durable but very rare gemstones. Although named after ...Gem ProfileSarcoliteSarcolite is an extremely rare mineral. Tiny, colorless to “fleshy pin...Gem ProfileScapoliteAlthough not well known, scapolite would make an attractive gem materi...Gem ProfileScheeliteLarge, faceted scheelites are among the most beautiful of all collecto...Gem ProfileScoroditeWith lovely colors and intense pleochroism, faceted scorodite is a pri...Gem ProfileSellaiteAn overview on Sellaite Jewelry and Gemstones. Covers details and esse...Gem ProfileSenarmontiteSenarmontite is a rare mineral, restricted in occurrence to the presen...Gem ProfileSeranditeTo date, only one locality — Mont St. Hilaire, Quebec, Canada — has pr...Gem ProfileSerpentineThe gem material known as serpentine actually encompasses several rela...Gem ProfileShattuckiteShattuckite is often mixed with quartz, and data often reported for pr...Gem ProfileShortiteShortite is an exceedingly rare, not overly attractive mineral. Cut ge...Gem ProfileSideriteSiderite is difficult to cut, but this light brown collector's gem has...Gem ProfileSillimaniteThe fibrolite from Burma and Sri Lanka is well known to gem collectors...Gem ProfileSimpsoniteSimpsonite is an extremely rare gemstone. The material from Western Au...Gem ProfileSinhaliteLong thought to be brown peridot, sinhalite was investigated in 1952 a...Gem ProfileSmaltiteSmaltite is a collectors oddity, cut only as cabochons. It is seldom s...Gem ProfileSmithsoniteSmithsonite occurs across the globe, but facetable crystals are extrem...Gem ProfileSmoky QuartzSmoky quartz comes in every shade of brown, from a light tan to nearly...Gem ProfileBuying GuideSodaliteTypically blue, durable, and easy to cut, sodalite is highly desired b...Gem ProfileSogdianiteSogdianite is an extremely rare mineral, suitable for cabochons. The c...Gem ProfileSpessartite GarnetUsually orange to reddish brown, gem-quality spessartite or spessartin...Gem ProfileBuying GuideSphaleriteSphalerite occurs in many colors. With a dispersion over three times t...Gem ProfileBuying GuideSphene (Titanite)Sphene, also known as titanite, has rich body colors, strong trichrois...Gem ProfileSpinelAlthough long known best for being misidentified as ruby, spinel is a ...Gem ProfileBuying GuideSpodumeneExtraordinarily difficult to cut, spodumene has several colorful varie...Gem ProfileBuying GuideSpurriteAn attractive but uncommon mineral, spurrite has seldom been cut as a ...Gem ProfileStar SapphireStar sapphire is a type of sapphire that displays asterism, a star-lik...Gem ProfileStauroliteStaurolite crystals in opaque cross shapes are popular gemstones. Howe...Gem ProfileStibiotantaliteRare stibiotantalite possesses an interesting mix of physical and opti...Gem ProfileStichtiteStichtite is not facetable, but the pink color is quite striking in ca...Gem ProfileStolziteStolzite is a rare mineral; much rarer than wulfenite and usually occu...Gem ProfileStrontianiteStrontianite is a collector’s oddity, with no spectacular properties t...Gem ProfileSugiliteWhat is the color of sugilite? Grape jelly purple is a good descriptio...Gem ProfileSulfur (Sulphur)Although sulfur is very abundant, facetable material is not. Sulfur is...Gem ProfileSunstoneSunstones contain hematite or goethite inclusions, which reflect light...Gem ProfileTaaffeiteTaaffeite reacts to most gemological tests like mauve-colored spinel, ...Gem ProfileTalcAn overview on Talc Jewelry and Gemstones. Covers details and essentia...Gem ProfileTantaliteTantalite is too dark to be of use as a faceted gem but is sometimes c...Gem ProfileTanzanite (Zoisite)Tanzanite has had a rapid rise to prominence among jewelers and gem en...Gem ProfileBuying GuideTektiteTektite is a natural glass formed from the ejected debris of meteorite...Gem ProfileTephroiteTephroite is generally reddish brown and barely translucent. However, ...Gem ProfileThaumasiteFor a long time, rare thaumasite crystals — pale, fragile, and with li...Gem ProfileThomsoniteThomsonite cabochons take a high polish but are somewhat brittle. Thes...Gem ProfileTiger's EyeCrocidolite, (blue asbestos,) alters to quartz, but while retaining it...Gem ProfileTopazThe traditional November birthstone, topaz is a popular gem. Although ...Gem ProfileBuying GuideTourmalineTourmaline is a name applied to a family of related minerals with wide...Gem ProfileBuying GuideTremoliteIt is possible to misidentify tremolite, mistaking it for other amphib...Gem ProfileTriphylite (Tryphylite)Triphylite is one of the world's rarest gems. The IGS had the extraord...Gem ProfileTsavorite GarnetAn emerald-green variety of grossular garnet, tsavorite is one of the ...Gem ProfileBuying GuideTugtupiteGem collectors prize tugtupite, the "Reindeer Stone," for its rich col...Gem ProfileTurquoiseWith striking sky blue to blue-green colors, turquoise has been prized...Gem ProfileBuying GuideUlexiteThe fibrous material cuts interesting catseye cabochon gems, but they ...Gem ProfileUvarovite GarnetAlways a dark, rich green color, uvarovite is one of the rarest member...Gem ProfileBuying GuideVanadiniteVery few vanadinites have ever been cut. This is unfortunate, since th...Gem ProfileVarisciteWith beautiful green to blue-green colors and interesting patterns, va...Gem ProfileVilliaumiteA little-known and rare collector’s gemstone, villiaumite is very diff...Gem ProfileVivianiteVivianite is so fragile and soft, any faceted gems would be difficult ...Gem ProfileVäyryneniteVäyrynenite is a very rare mineral. Crystals as well as faceted gemsto...Gem ProfileWarditeWardite is another of the many phosphates that have been cut by collec...Gem ProfileWavelliteWavellite is a very attractive mineral, well-known to collectors. Its ...Gem ProfileWeloganiteTruly a collector’s gem, weloganite is very rare and seldom cut. This ...Gem ProfileWhewelliteSeldom seen even in mineral collections, whewellite is very rarely fac...Gem ProfileWilkeiteAn overview on Wilkeite Jewelry and Gemstones. Covers details and esse...Gem ProfileWillemiteWillemite is prized for its intense green fluorescence. Too fragile fo...Gem ProfileWitheriteEasy to cut but too soft and fragile for jewelry, a faceted witherite ...Gem ProfileWollastoniteInteresting cabochons have been cut from wollastonite, especially from...Gem ProfileWulfeniteAlthough aesthetically magnificent wulfenite crystals are often too th...Gem ProfileXonotliteXonotlite is strong and can take a good polish. However, these gems ar...Gem ProfileYellow DiamondWhen someone mentions diamonds, the first image that most people think...Gem ProfileYugawaraliteYugawaralite is a very rare colorless to pinkish zeolite mineral. Litt...Gem ProfileZektzeriteSmall, cuttable crystals of very rare zektzerite are found only in a m...Gem ProfileZinciteZincite is a very rare mineral. It’s also difficult to cut, which make...Gem ProfileZirconDon’t be confused by the name. Zircon is a natural, magnificent, and u...Gem ProfileBuying GuideZunyiteAn overview on Zunyite Jewelry and Gemstones. Covers details and essen...Gem ProfileNever Stop LearningWhen you join the IGS community, you get trusted diamond & gemstone information when you need it.Become a MemberGet Gemology InsightsGet started with the International Gem Society’s free guide to gemstone identification. Join our weekly newsletter & get a free copy of the Gem ID Checklist!Email AddressSubmitThe International Gem Society (IGS) is the world's top resource for gem professionals, enthusiasts, and industry content.support@gemsociety.orgLearning CenterGemologyGemstone EncyclopediaJewelry & LapidaryDiamond Buying AdviceGemstone Price GuideExpert Buying GuidesCoursesIGS Mini CoursesProfessional Gemologist CertificationDiamond Specialist CertificationAboutAdvertiseContactFaqSupportPressMembership© 2024 International Gem Society LLC. All rights reserved.Privacy PolicyTerms of UseAffiliate DisclosureAccessibility Statement

什么是澳大利亚GEMS认证？ - 知乎

什么是澳大利亚GEMS认证？ - 知乎切换模式写文章登录/注册什么是澳大利亚GEMS认证？CTC华商检测​已认证账号为了提高电器设备和各行业(住宅，商业和工业)产品能源利用效率，提升经济和环境效益，澳大利亚和新西兰颁发了温室和能源标准法规(Greenhouse and Energy Minimum Standards Bill 2012，简称GEMS)，并于2012年10月1日起生效。新的GEMS法规不仅涵盖了以往主要政策：强制性的能源性能标准(简称MEPS)，能源的效益标签(简称ERLS)以及设备能源效率计划(简称E3)，并且把能源效益扩大到减少温室气体排放和提升能源利用效率的范畴，从企业和消费者在整个产品生命周期运行成本的角度，做出合适的选择。 从2012年10月1日起，澳大利亚和新西兰将以能效认证GEMS认证，用于取代之前的澳洲能效MEPS认证。GEMS认证属于强制性认证，在管制内的产品必须有GEMS认证才可以在市场上销售，且申请人必须为澳洲本地注册的公司。（GEMS认证标志）目前GEMS认证管制的产品有： 紧凑型荧光灯、特低电压转换器、双端荧光灯、荧光灯镇流器、白炽灯、洗衣机、干衣机、洗碗机、外部电源、电视、数字机顶盒、电热水器、空调和热泵、三相电动机、家用制冷器具、制冷塔/精密空调、商用冰箱、陈列柜、配电变压器等GEMS认证流程：1、选择产品进行测试，测试依据的标准与原MEPS认证一致，一般来说只要是ISO 17025认可实验室提供的测试报告皆可获得认可；2、提交测试报告等资料进行GEMS注册，资料审核通过后将获得GEMS认证证书。新的GEMS法规主要在注册方面有了新的要求，申请人不能选取单个州进行注册，而是统一到Australian Regulator进行注册，并且根据产品类别，注册期限为5年。GEMS认证需要的资料：1、Application form及授权信；2、Product Label（需含有相应认证标志）；3、Product Photo要求进行工厂检查的国家通常都需提供，但通常可以接受CIG 023工厂检查报告；GEMS认证周期：测试1周，注册需2周。点击查看：编辑于 2020-07-01 15:09国际标准化组织（ISO）质量认证认证​赞同 1​​添加评论​分享​喜欢​收藏​申请

International Gem Society IGS - Information and educational services for everyone interested in gemstones

rnational Gem Society IGS - Information and educational services for everyone interested in gemstonesMEMBERSHIPSearchLearning CenterGemologyScience, tools, identification, treatment, valuation & grading of gemsJewelry & LapidaryGemstone jewelry settings, metals, tools, cutting & faceting stonesGemstone EncyclopediaList of all gemstones from A-Z with in-depth information for eachGem Photo GalleryThousands of gem photos searchable by various properties.Diamond Buying AdviceEverything you need to know about buying your perfect diamondBirthstonesLearn more about these popular gemstones, their meaning & about buying birthstone jewelryGem PricingGemstone Price GuidesPrice guidance on over 70 types of gemstonesExpert Buying GuidesIn-depth guides to quality factors of the 40 most popular gemstonesCoursesOverviewMini CoursesProfessional Gemologist CertificationDiamond Specialist CertificationCommunityGem BusinessesView AllAppraisalsAuctionsGem CuttingGem TreatingGemological LaboratoriesGemology Supplies & EquipmentGemstonesInformational ResourcesJewelryLapidary Supplies & EquipmentRough Gems & Mineral SpecimensAboutAbout IGSAdvertiseContact UsFAQSupportPressGet trusted diamond and gemstone information when you need itInformation and educational services for everyone interested in gemstones. For gemologists, hobbyists, jewelers, lapidaries and everyone in between.Become a MemberGet Gemology InsightsLearn how to get started with the International Gem Society’s guide to gemstone identification. Join our weekly newsletter & get a free copy of the Gem ID Checklist!Email AddressSubmitYour stepping stone to a gemology education or career The Learning Center1800+ articles and videos. 15+ courses. All available on demand.Learning CenterGem PricingA retail Gem Price Guide that instantly gives you gem values.Gem Price GuideCommunityGet answers to your questions from gem experts and peers in our forum. ForumJoin our thriving community 1700+Articles10,000+Members400+Lessons250+BusinessesWhat people are saying" I have never known or heard of an organization that offers so much for its members, and at such a low cost. What started as a hobby in 1998 and now is a small home business for my wife and I has been made so much easier by the information you supply. Thank you. "Ernest and Peggy Roisch, Rainbow Rocks, LTD IGS Member" You know the best thing that I have learnt from your great courses is that it does not matter how much you think you know about gems, you never stop learning, each day there is something more learn, it will never stop. Thank all for the help, education and support that you give IGS members. "Peter CheckleyIGS Member" I have been on the distant sidelines of the jewelry business for a long time with a great love of colored stones and working with gold. I must tell you that IGS is a Godsend for me, as I do not have the resources or the six months required to get a GG from the GIA now. "Charlie BernheiserIGS MemberHow will IGS help you? 84%LearnMembers who use the Learning Center to identify gemstones68%ConnectMembers who use the forum to connect with other gem lovers52%NegotiateMembers who use the Gem Price Guide to value their gemstones47%CareerMembers who have taken IGS courses to accelerate their gemology careerBecome a Gemology ProExplore your favorite gemstones with our step-by-step Mini Courses (250+ lessons)Option to take our two in-depth Certification Courses to accelerate your careerA listing in the IGS Business Directory which can be discovered by our 500,000+ monthly website visitorsGemstone pricing data at your fingertipsAccess to hundreds of premium members-only articlesBecome a MemberThe world’s most comprehensive gemstone libraryGuaranteed to spark inspiration and learningGem EncyclopediaStart ExploringDiamond Buying AdviceStart LearningGem Price GuideAppraise Your Own GemsPopular ArticlesMore ArticlesBirthstone ChartWhat are the birthstones by month? January is garnet, February is amethyst, March is aquamarine, April is diamond, May is...Read More37 Blue Gemstones (Names, Pics, & More)Symbolic of sea and sky, blue has always been a popular color for gems. Learn how to assess color in...Read MoreGemstone Hardness and WearabilityGemstone hardness measures resistance to scratching. A gem's wearability grade takes hardness into account, but it’s only one of many...Read More10 Rare Engagement Ring Stones that Won’t Break the BankNot all rare gemstones cost a fortune. If you’re looking for something different but affordable for your wedding, here are...Read MoreLatest Community DiscussionsJoin the DiscussionTanzanian CorundumRead MoreIs This a Topazolite Garnet?Read MoreNigerian GemstonesRead MoreIs This an Opal?Read MoreThe International Gem Society (IGS) is the world's top resource for gem professionals, enthusiasts, and industry content.support@gemsociety.orgLearning CenterGemologyGemstone EncyclopediaJewelry & LapidaryDiamond Buying AdviceGemstone Price GuideExpert Buying GuidesCoursesIGS Mini CoursesProfessional Gemologist CertificationDiamond Specialist CertificationAboutAdvertiseContactFaqSupportPressMembership© 2024 International Gem Society LLC. All rights reserved.Privacy PolicyTerms of UseAffiliate DisclosureAccessibility Statement