YAG with Flux-Filled Fingerprints
The author recently examined a 3.58 ct yellowish green yttrium aluminum garnet, a manufactured product known in the trade as “YAG,” that contained numerous large flux-filled fractures.
New Emerald Locality in Southern California
Located about 60 miles east of San Diego, a new emerald deposit has been discovered in the Julian Mining District.
An Interesting Rose Quartz from Madagascar
A new find of rose quartz from Madagascar contained some unusual inclusions.
“Diffusion Ruby” Proves to be Synthetic Ruby Overgrowth on Natural Corundum
A relatively new production of red corundum, reportedly from Bangkok, has been offered for sale in recent years.
Microscopic Shells in Natural Pearls from Pinctada radiata
Two pearls from Bahrain containing minute shells are examined at GIA’s Mumbai laboratory.
Plastic Deformation: How and Why Are Most Diamonds Slightly Distorted?
New Deposit of Black Opal from Ethiopia
The Stayish mine in Ethiopia’s Wollo province has been producing black opal since 2013.
34th International Gemmological Conference
A report from the 34th IGC, held in Vilnius, Lithuania in August 2015.
Spectral Reflectance and Fluorescence Characteristics of Natural-Color and Heat-Treated “Golden” South Sea Cultured Pearls
A comparison study was made between the yellow and white nacre of the gold-lipped Pinctada maxima oyster shell and 65 yellow cultured pearls.
Identification of “Pistachio” Colored Pearls Treated by Ballerina Pearl Co.
A report on the color treatment process for these intensely greenish yellow to yellowish green cultured pearls and the techniques for identifying them.
A Pearl Identification Challenge
Two pearls presented a unique challenge, as testing at three different gemological laboratories could not conclusively identify them as natural or cultured, determine a freshwater or saltwater growth environment, or specify the producing mollusk.
HPHT-Processed Diamond Fraudulently Represented as Untreated
An HPHT-treated round brilliant diamond with an inscription that presents as a GIA report number is found to be inconsistent with the institute's report, previously issued for an untreated diamond.
A Useful Technique to Confirm the Hydrophane Nature of Opal
Observing a water drop’s interaction with opal, as well as refractive index, can confirm a specimen’s hydrophane nature with less risk of breakage than total immersion.
Hydrophane Opal Treatment
An opal rough is immersed in water and treated with oil and Opticon to observe effects on transparency and play-of-color.
Gemological Characteristics of Saltwater Cultured Pearls Produced After Xenotransplantation
X-ray Computed Microtomography: Distinguishing Natural Pearls from Beaded and Non-Beaded Cultured Pearls
The distinction of natural from cultured pearls traditionally has been based on X-radiography.
15.53 ct Pearl Discovered in Edible Oyster from the Ostreidae Family
A large natural pearl discovered in an edible oyster offers insight to the scientific pearl community.
“Gran Dama” Brooch Featuring Large Melo Pearl
The centerpiece of this brooch is a 98.67 ct Melo pearl, believed to be one of the world's largest.
Faceting Transparent Rhodonite from Broken Hill, New South Wales, Australia
Transparent rhodonite is considered one of the most difficult of all gems to facet because of its perfect cleavage and brittle, uneven fracture.
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