Blue sapphires are currently being mined on an exploratory basis from alluvial deposits at the Lindi mine, near the town of Mingxi in Fujian Province. The geology and occurrence of the sapphires ...

Although lost for literally hundreds of years after the Spanish conquest of the Aztecs, many deposits of jadeite have been found in Guatemala during the last two decades. Following the discovery of ...

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 ...

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 ...

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 ...

Learn more about programs and courses offered at GIA's campus in New York City and worldwide, including admission requirements, class schedules, and academic policies. Stay in touch - complete the ...

Established in 1931, the Gemological Institute of America (GIA) is the world’s foremost authority on diamonds, colored stones, and pearls. A public benefit, nonprofit institute, GIA is the leading ...

Because laboratory-grown diamonds are essentially chemically and optically the same as natural diamonds, traditional gemological observations and instrumentation are not able to tell them apart. GIA ...

Fine-color, large, and eye-clean (lacking visible inclusions) rubies like this 11.01carat (ct) stone from Myanmar (formerly known as Burma) are extremely rare and valuable. – Photo: Robert Weldon/GIA.

合成宝石材料是在实验室中制成的一种材料，但却具有与其相对应的天然矿物相同的化学、光学和物理特性，虽然在某些情况下，如合成土耳其石和合成蛋白石，可能会有其他化合物的存在。

A look at the history of analytical instruments used for gem testing. UV-Vis-NIR spectroscopy measures how gemstones absorb and interact with light across the ultraviolet, visible, and near-infrared ...

To address concerns about laboratory-grown and treated diamonds being mixed into parcels of melee, GIA has developed an automated system to analyze and sort melee-size diamonds quickly and accurately.