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 ...

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 ...

An emerald deposit at Byrud, in southern Norway, yielded significant quantities of crystals and gem rough in the late 19th and early 20th centuries. Complex multiphase inclusions in the emeralds ...

This little-known source of gem-quality peridot, located in southwestern New Mexico, produces small but brilliant gems. Kilbourne Hole peridot is found in the explosion debris of a 180,000-year-old ...

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 ...

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 ...

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 ...

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 ...

Figure 1. These two musgravites (0.11 and 0.24 ct) are reportedly from Myanmar. Photo by Brad Payne. Two small, near-colorless stones reportedly from Myanmar (0.11 and 0.24 ct; figure 1) were recently ...

A synthetic gem material is one that is made in a laboratory, but which shares virtually all chemical, optical, and physical characteristics of its natural mineral counterpart, though in some cases, ...

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.

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 ...