Research Article Search Results
34th International Gemmological Conference
A report from the 34th IGC, held in Vilnius, Lithuania in August 2015.
Sapphires from Thammannawa, Kataragama Area, Sri Lanka
The February 2012 discovery of high-quality blue sapphires at Thammannawa near Kataragama in southeastern Sri Lanka has intensified gem mining and exploration in the surrounding area and all over the country.
Enormous South Sea Cultured Pearl Filled with Cultured Pearls
An unusually large cultured pearl was filled with multiple cultured pearls, perhaps after the emergence of an original single-bead nucleus.
The Seven Types of Yellow Sapphire and Their Stability to Light
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?
“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.
Vibrantly Colored Gems
Bill Larson of Pala International reports a very strong AGTA Tucson show.
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.
“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.
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.
