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An exceptionally large and clean 1.91 ct faceted oval brilliant afghanite.

Large Faceted Afghanite

Hollie McBride, August 9, 2018

A report on the largest facet-grade afghanite seen in the GIA gem identification department.

A Repaired Diamond

Troy Ardon, August 9, 2018

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

Quartzite dyed to resemble ruby-in-zoisite.

Dyed Quartzite Imitation of Ruby-in-Zoisite

HyeJin Jang-Green, January 26, 2018

Beads appearing to be ruby-in-zoisite are revealed to be dyed quartzite.

CVD Synthetic Diamond Over 5 Carats Identified by GIA

Billie “Pui Lai” Law and Wuyi Wang, January 27, 2017

Results from GIA’s recent testing of a 5.19 ct CVD synthetic diamond, the largest it has examined to date.

Non-Nacreous Purple and White Pearls Reportedly from Spondylus Species

Artitaya Homkrajae, November 7, 2016

Examination of pearls with a dominant purple hue, reportedly from the Spondylus calcifer mollusc.

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.

Unusual Coloured Stones

Rebecca Tsang, April 28, 2016

Six rarely seen gemstones are submitted as a parcel to the Carlsbad lab.

5.03 ct Fancy Deep Blue HPHT Synthetic Diamond

Largest Blue HPHT Synthetic Diamond

Kyaw Soe Moe, Paul Johnson, Ulrika D’Haenens-Johansson, and Wuyi Wang, April 28, 2016

Analysis of a 5.03 ct HPHT-grown blue synthetic diamond, the largest ever examined by GIA.

Synthetic quartz bangle examined in Bangkok.

Synthetic Rock Crystal Quartz Bangle with Unusual Inclusions

Nattida Ng-Pooresatien, February 1, 2016

A high-quality bangle with two-phase inclusions, similar to natural quartz is found to be synthetic material.

Freeform topaz under daylight-equivalent light.

Polished Freeform Topaz Imitating Diamond Rough

Akhil Sehgal and Riccardo Befi, November 23, 2015

Material submitted as a rough diamond is revealed through gemmological testing and analysis to be a near-colourless topaz.

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