The stony-iron meteorites known as pallasites are famed for the areas of yellowish green olivines they contain. Since the earliest description by Peter Simon Pallas in the 18th century, reference has ...

The gemological properties of synthetic green and lavender jadeite, which has been manufactured by the General Electric Company on an experimental basis, are summarized. The synthetic jadeites ...

This collection includes a palette of beautiful cultured pearls. Besides round golden white loose cultured pearls, there’s a strand of well-matched round whites and a strand of oval pastel colors. The ...

Commercial quantities of gem-quality benitoite are known from a single location in the world, the Benitoite Gem mine in the New Idria district of San Benito County, California. A barium titanium ...

GIA 与北大资源研修学院 (Peking University Resource College) 开展合作办学项目，在深圳提供校园课程、实习班和学生工作室。这些课程由 GIA 老师用中文授课。 除非另有说明，所有课程均用中文授课。 2024 年课程时间表 开课日期并不包括新生报到日 。 如需了解关于 ...

Diamond “type” is a concept that is frequently mentioned in the gemological literature, but its relevance to the practicing gemologist is rarely discussed. Diamonds are broadly divided into two types ...

Although various forms of paints and coatings intended to alter the color of diamond have likely been in use for almost as long as diamonds have been valued as gems, the modern era of diamond ...

Diamond color is all about what you can’t see. Diamonds are valued by how closely they approach colorlessness – the less color, the higher their value. (The exception to this is fancy color diamonds, ...

The GIA Laboratory-Grown Diamond Report includes full quality assessment with a plotted clarity diagram. Color and clarity specification are described on the same scale as the GIA Diamond Grading ...

A color-change sapphire was recently submitted to the GIA lab in Carlsbad for an origin determination report. The 5.68 ct transparent cushion mixed cut displayed a strong color change from grayish ...

Amethyst may develop into the more common citrine and rarer green quartz naturally under certain geologic conditions. On the California-Nevada border, just north of Reno, amethyst, citrine, and green ...