The history of Baja California has been closely tied to the exploitation of pearls since the 16th century.

This article presents information about the CVD process, the history of its development, and properties that differentiate the resulting synthetic crystals from natural diamond.

The distinction of natural from cultured pearls traditionally has been based on X-radiography. X-ray computed microtomography (μ-CT) has recently been applied to gain more insight into pearl ...

The Graduate Diamonds online diploma coursework is a combination of one online course and one hands-on lab class. Lab classes are offered at GIA campuses worldwide. Diamonds and Diamond Grading - ...

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.

Ruby and sapphire are varieties of the mineral corundum. - Courtesy Hamilton Jewelers Ruby is one variety of the corundum mineral species, which also includes sapphire. Ruby is highly regarded and can ...

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 ...

This 5.30-carat emerald from Brazil has a slightly bluish green color. Courtesy John Parrish, courtesy African, Brazilian, Colombian Gems Incorporated. Emerald has many special qualities, but colored ...

A guide describing frequently encountered gem treatment processes, their detection, and special care tips for treated gems.

这颗克什米尔蓝宝石拥有强烈的天鹅绒般蓝色。——摄影：Robert Weldon（罗伯特·韦尔登）/GIA。 蓝宝石是有色宝石三巨头之一，另外两种是红宝石和祖母绿。人们把这种坚固的宝石定为 九月生日石，它以实用性和浪漫气息吸引了众多珠宝买家。 红宝石和蓝宝石均属于刚玉矿物。红色的刚玉称为红 ...

Abstracts of speaker presentations from the “Colored Stones and Pearls” session of GIA’s 2018 International Gemological Symposium.

Emerald is the green to greenish blue variety of beryl, a mineral species that also includes aquamarine as well as beryls in other colors.