Cabochons Fashioned from the Shell of Crassostrea Virginica
The Carlsbad lab examines gem materials fashioned from American oyster shells.
Unique Star Sapphire with Transparent Core
A sapphire cabochon with an unusual appearance is seen at GIA’s Tokyo lab.
Two Natural “Horse Conch” Pearls
Rare pearls, along with their shell, are studied in the Hong Kong 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.
Gota de Aceite in a Zambian Emerald
A phenomenon usually seen in Colombian emeralds is found in a specimen from Zambia.
Synthetic Moissanite Imitating Rough Diamond
A light green specimen, submitted as a rough diamond, is actually a synthetic moissanite.
Cat’s-Eye Alexandrite with Unique Inclusion Pattern
Examination of a chatoyant alexandrite cabochon.
Lizard Skin on Deformed Diamond
The surface texture of a diamond is affected by the gemstone’s structure.
Two Unusual Natural Sapphires with Synthetic Ruby Overgrowth
For the first time, the Carlsbad and New York labs see natural sapphire seeds with synthetic ruby overgrowth.
Partially Hollow Tridacna Blister Pearls with Shells Attached
Blister pearls attached to shells are seen in both the Bangkok and the New York laboratories.