Large Natural Fossil Blister Pearls from Tridacna (Giant Clam) Species
Two blister pearls attached to a host shell believed to have fossilized during the later Pleistocene period and discovered in southeastern Kenya are studied.
A Natural Pearl with an Intriguing Internal Structure
A semi-baroque pearl with an unusual radial feature is submitted to the Bangkok lab for testing.
Graphite Inclusions Forming Octahedral Outline in Diamond (英語)
An inclusion outlined by minute graphite crystals within a diamond create an octahedral shape.
Two Large CVD-Grown Synthetic Diamonds Tested by GIA (英語)
Two near-colorless rounds, weighing 3.23 and 2.51 ct, were the largest CVD-grown synthetic diamonds GIA has examined.
Uranium Contents of Hyalite
The fluorescence of hyalite from Zacatecas, Mexico is examined and compared to material from other locations in GIA’s Tokyo lab.
Two Large Natural Pearls Reportedly from Spondylus and Trochoidea Species Mollusks
Natural pearls of unusual size and unique appearance are retrieved from the west coast of Mexico and examined in GIA’s New York lab.
Very Large Type Ib Natural Diamond
A 13.09 ct. Fancy yellow rough diamond, with C centers causing the intense color, is seen in the New York lab.
Synthetic Rock Crystal Quartz Bangle with Unusual Inclusions
A high-quality bangle with two-phase inclusions, similar to natural quartz, is found to be synthetic material.
Treated Pink Diamond with HPHT Synthetic Growth Structure
A Fancy pink type IIa diamond showing cuboctahedral growth and greenish blue phosphorescence is shown to be a natural, treated colored diamond.