Article Search Results

Rare Faceted Wurtzite

Amy Cooper and Nathan Renfro, July 25, 2014

A stone submitted for identification is revealed to be the first wurtzite examined by the GIA lab.

Fluorite Sphere with Phosphorescent Coating

Nathan Renfro, July 31, 2015

A sphere with unusual phosphorescence is seen in the Carlsbad laboratory.

A Repaired Diamond

Troy Ardon, August 9, 2018

A marquise-cut diamond is found to have been broken and reassembled with an unknown adhesive.

Strong Colour Zoning in Diamond Reflects Complex Growth Environment

Troy Ardon, GIA, July 1, 2013

A report on a 2.08 ct emerald-cut diamond graded as fancy dark orangey brown.

Rare Faceted Neptunite

Amy Cooper and Tara Allen, GIA, July 1, 2013

Raman spectroscopy reveals orangey red neptunite - the first examined by GIA - in the identification of a 11.78 ct faceted “black” octagonal modified step-cut stone.

A Large Irradiated Green-Yellow Diamond

Wuyi Wang, Paul Johnson, and Emiko Yazawa, GIA, July 1, 2013

GIA's identification of a large diamond as artificially irradiated based on careful spectroscopic analysis and lab database review.

Large synthetic moissanite with silicon carbide polytypes

Kyaw Soe Moe, Paul Johnson, and Ren Lu, January 31, 2014

Examination of the properties of a synthetic moissanite specimen submitted as a black diamond.

Separation of Black Diamond from NPD Synthetic Diamond

Paul Johnson and Kyaw Soe Moe, August 3, 2016

DiamondView is used to differentiate a Fancy black natural diamond from its NPD synthetic counterparts.

CVD-Grown Synthetic Diamond with Aggregated Nitrogen Impurities

Troy Ardon, Tara Allen, and Christopher M. Breeding

Recently, an unusual 0.94 ct Fancy yellow-brown emerald was submitted to GIA for a synthetic diamond grading report. It contained a cloud of black needle-like inclusions occurring along a plane and showed weak green transmission with fibre-optic illumination.

Unusual Curved Colour Zoning In Emerald

Nathan Renfro, Vincent Pardieu, and Supharart Sangsawong, GIA, July 1, 2013

A report on a 1.17 ct emerald obtained in Kabul, Afghanistan for GIA's permanent reference collection

Article Search Results

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Gemstones

Article Search Results

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Gemstones

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