Irreversible Photochromism in Synthetic Sapphire
The first documented case of corundum with irreversible photochromism encountered at GIA.
Rock Crystal Quartz Skull
A remarkable skull carved from quartz crystals mined in Arkansas is submitted to the Carlsbad laboratory.
Natural Non-Nacreous Pearls from Various Marine Mollusks
The Bangkok laboratory studies 35 loose non-nacreous pearls from a wide range of marine mollusk species.
Enormous South Sea Cultured Pearl with Filled and Partially Hollow Structure
Examination of a gigantic South Sea bead cultured pearl reveals an intriguing internal structure.
Assembled Bead Cultured Half-Pearl
Investigation in the Carlsbad laboratory reveals a pearl submission is not mabe as initially believed.
Black Opal with Unique Play-of-Color
A black opal cabochon set in a ring displays vivid orange play-of-color.
Fancy Vivid Yellow HPHT-Grown Diamonds
A report on a submission of 26 yellow HPHT-grown diamonds from the Hong Kong laboratory.
CVD Laboratory-Grown Gem Diamonds from Plasmability
A report from the New York laboratory on colorless and near-colorless CVD gem diamonds produced by the Texas-based company Plasmability.
CVD-Grown Diamond with an Unusual Blue Band
An HPHT-treated CVD-grown diamond displaying a blue growth band is examined in the Mumbai laboratory.
Checkered Pattern on Diamond
The Mumbai laboratory examines a modified pear portrait-cut natural diamond.
Rare Gem-Quality Viitaniemiite
