Amethyst Gemstone | Amethyst Stone - GIA
Amethyst Gemstone is the purple variety of the Quartz mineral. Amethyst’s purple color can range from a light lilac to a deep, intense royal purple, and from brownish to vivid.
Amethyst Description - GIA
Amethyst Description. This amethyst crystal is from Namibia. It shows classic quartz crystal shape: a six-sided columnar crystal with a pyramid-shaped termination at the top. Courtesy Daniel Trinchillo, Fine Minerals International. Amethyst is the purple variety of the quartz mineral species.
Amethyst - Gemological Institute of America
Amethyst is a gem with purple coloring that many people find very beautiful. It is the purple variety of the mineral quartz. It was as valuable as ruby and emerald until the 1800s when more amethyst was found in the country of Brazil. It is the most valuable quartz gem.
Amethyst History and Lore - GIA
Amethyst is the birthstone for February and one of the emblems of the twelve apostles. Fine amethysts have been set in religious jewelry and royal crown jewels for ages. It was once considered equal in value to ruby, emerald, and sapphire.
Amethyst Quality Factors - GIA
Amethyst Quality Factors. This 17.53-carat amethyst displays a rich reddish purple color. - Lydia Dyer, Super Trillion Cut Amethyst gem courtesy of John Dyer & Co. Amethyst has been the most-prized quartz variety for centuries.
紫水晶 | 紫水晶 - GIA
关于紫水晶. 查看图库. 直到 19 世纪在巴西发现大型矿床，紫水晶曾经与红宝石和祖母绿一样昂贵。. 有人认为它可以防止中毒—amethystos 在古希腊语中表示“不醉”之意。. 如今，作为最有价值的石英类别，紫水晶备受设计师作品和同类大众市场珠宝的亲睐，其 ...
Amethyst Buying Guide - GIA 4Cs
2014年2月1日 · Breathtaking and surprisingly affordable, it’s also the most valued variety of quartz. If you’re in the market for this February birthstone, GIA’s Amethyst Buying Guide has tips and advice on what to look for, including amethyst quality factors.
Amethyst Care and Cleaning Guide - GIA
Ultrasonic cleaners are usually safe except in the rare instances where a stone is dyed or treated by fracture filling. Steam cleaning is not recommended, and amethyst should not be subjected to heat. Learn about amethyst's durability and how to care for your amethyst jewelry.
Moroccan Amethyst: Mining and Marketing | Gems & Gemology
2015年4月30日 · Characteristic “hourglass” color zoning (figure 1) and striking red hematite “finger” inclusions help distinguish Moroccan amethyst. Although amethyst is readily available on the market, the material from Boudi in southern Morocco stands out.
Pleochroism in Faceted Gems: An Introduction | Gems
This article discusses this phenomenon in doubly refractive gemstones, specifically as it relates to overall color appearance in faceted gems. Contrary to popular belief, pleochroism can be visible in faceted gems even when they are cut with an optic axis parallel to the direction of view.