The 1980s have seen an explosion of interest in the cultured black pearls of French Polynesia, five groups of island archipelagos in the South Pacific. Twenty years ago, black pearls were a mere ...

Malaya garnets from Bekily, Madagascar, are predominantly pink to pinkish orange, with some stones orange to red. Discovered only in the late 1990s, the majority are intermediate members of the pyrope ...

Jewelry-quality synthetic malachite is now being manufactured in the USSR. The texture, structure, and physical and physico-chemical properties of this synthetic malachite are reported. Three textural ...

The modern elephant, threatened by extinction, is protected by international agreements banning the sale of ivory from tusks. This trade ban does not apply to ornaments made of mammoth fossil ivory, ...

Four similar-appearing yellowish green samples from Block D at Merelani, Tanzania, were identified as diopside and tremolite. The gems are identical in color, but their standard gemological properties ...

Studies carried out at the DTC Research Centre have shown that single-crystal CVD synthetic diamond is clearly distinguishable from natural diamond. This article presents information about the CVD ...

Figure 1. The largest known natural moissanite crystal, found along the Kishon River in northeastern Israel, measures 4.1 mm in its longest dimension. Photo by Vered Toledo. Synthetic silicon carbide ...

Twenty-six peridot samples from the Esquel pallasite meteorite and 27 samples from 10 terrestrial sources were studied by laser ablation–inductively coupled plasma–mass spectrometry (LAICP- MS). Among ...

Vivid blue, green, and purple-to-violet cuprian elbaites, renowned in the gem trade as “Paraíba” tourmalines, continue to be recovered in small amounts from northeastern Brazil. Since the initial ...

GIA Student Workrooms give you affordable access to all the equipment and gemstones you need to complete the practical requirements of your Gem Identification course through Online Education. This ...

GIA Student Workrooms give you affordable access to all the equipment and gemstones you need to complete the practical requirements of your Gem Identification course through Online Education. This ...