This large Australian light opal cabochon weighs 117.85 carats. Small play-of-color flashes of orange and green predominate in a pinfire pattern, with spots of a more muted blue over a grayish ...

Copper-bearing tourmaline from Mozambique was first recovered in 2001, but its Cu content was not recognized until 2003, and it was not widely sold with its Mozambique origin disclosed until 2005. It ...

Akoya pearls are the small white pearls that most people picture when they think of pearls. They are saltwater pearls, and are usually round and white or cream, with a pink overtone and high luster.

Bengal International Jewellery Show, east India's largest B2B jewellery exhibition, continues the pursuit of displaying "Calcutta Handcrafted Jewellery" to the world, providing new horizons for the ...

Hydrothermal synthetic red beryl has been produced for jewelry applications by the Institute of Crystallography and an affiliated company, Emcom Ltd., both in Moscow. Diagnostic identification ...

GIA IT will be performing maintenance on our internal systems from Friday, October 18th (5 PM PT) to Saturday, October 19th 2024 (8 PM PT). During this maintenance window, the My Lab application, ...

As a consumer, you will regularly encounter in the marketplace gems that have been treated to change their appearance. A topic that often comes up is whether a particular gemstone is or isn’t treated.

这颗 122.70 克拉的丹泉石收藏在史密森尼国家自然历史博物馆。- Chip Clark（奇普·克拉克），由史密森学会友情提供 丹泉石是有色宝石系相对较新的成员。随着最常见的丹泉石采矿热潮的发展 ...

Due to the overwhelming popularity of GIA’s limited time, no-charge offer, all GIA Essentials classes starting in May and June – the period of the offer – are full. The offer is closed and we cannot ...

This sapphire from Kashmir has an intense velvety blue color. – Photo: Robert Weldon/GIA. Sapphire is one of the Big three of jewelry colored gemstones—the other two are ruby and emerald. A durable ...

This 7.19-carat alexandrite was cut to feature its beautiful color change. When the light source changes from daylight to incandescent light, the gem’s color changes from bluish green to reddish ...

Diamonds have a long history as beautiful objects of desire. In the first century AD, the Roman naturalist Pliny stated: “Diamond is the most valuable, not only of precious stones, but of all things ...