This ancient necklace dates to 2000BCE. An inscription on the center stone is a South Arabian script from the 8th century BCE. - From "Gems and Gemstones: Timeless Natural Beauty of the Mineral World" ...

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Students examine the technical expertise needed to grade, buy, and sell diamonds with the insight of a seasoned professional. Coursework explores the GIA diamond grading procedures to assess the 4Cs – ...

Students explore more than 60 species of common and collector gemstones found in the marketplace. Subjects covered include the GIA Colored Stone Grading System, gemstone formation, composition, ...

Harness the power of knowledge with the industry-leading instruments that GIA uses in its grading laboratories. Representing more than 85 years of research and the combined expertise of GIA’s ...

GIA is proud to provide the most comprehensive research in the industry with a world-renowned field gemology team and a dedication to acquiring colored stones directly from the source. Our ...

Emeralds are again being mined in the historic district of the Ural Mountains. Physical, chemical, spectroscopic, and microscopic characteristics of stones from the recent production are presented and ...

Synthetic emeralds grown hydrothermally in an alkali-free, chlorine-bearing solution have been manufactured in Guilin, China, since 1987. Diagnostic microscopic features include growth and color ...

Attractive yellow to light greenish yellow gem scapolites have been mined from a skarn deposit near the town of Ihosy, in southern Madagascar, since the late 1990s. Chemical analysis indicates that ...

Large crystals of chromium-containing synthetic forsterite are being commercially manufactured for use as a laser material. Considerable color variation is possible, and some of this material ...

A 43-carat alexandrite in the collection of the British Museum. Abundant alexandrite deposits were first discovered in 1830 in Russia’s Ural Mountains. Those first alexandrites were of very fine ...

The green turquoise cabochon, from an American mine, might become part of a designer’s unique jewelry piece. The even blue color of the cabochon on the right would be called “Persian blue” in the ...