Two Natural “Horse Conch” Pearls
Rare pearls, along with their shell, are studied in the Hong Kong lab.
Unique Star Sapphire with Transparent Core
A sapphire cabochon with an unusual appearance is seen at GIA’s Tokyo lab.
A Repaired Diamond
A marquise-cut diamond is found to have been broken and reassembled with an unknown adhesive.
Beryl and Glass Assemblage Imitating Emerald
An unusual assembled stone is examined at GIA’s New York lab.
Three Irradiated CVD Synthetic Diamonds
Irradiated CVD-grown diamonds are examined in the Carlsbad lab.
A Cat’s-Eye Rock Consisting of Jadeite and Amphibole
Raman spectroscopy reveals that a green bead, showing chatoyancy on one side, comprises jadeite and amphibole.
Large Faceted Afghanite
A report on the largest facet-grade afghanite seen in the GIA gem identification department.
Large HPHT-Treated Blue Type IIb Diamond
Properties of, and theories on colour zoning exhibited by, the largest HPHT-treated blue diamond graded by GIA.
One Natural Melee Diamond Found in Large Batch of HPHT Synthetic Melee
A single natural diamond is found within the largest percentage of undisclosed synthetic melee submitted to GIA.
15 Carat HPHT Synthetic Diamond
A synthetic diamond seen in the Carlsbad lab is the largest faceted lab-grown diamond examined by GIA.