Ponderosa Sunstone Update
The president of Oregon’s Desert Sun Mining and Gems provides the outlook for activity at the Ponderosa sunstone mine.
Potentate’s Montana Sapphire Mine: An Interview with Warren Boyd
An update on the activity at Potentate’s Montana deposits.
Chatoyant Quartz/Tourmaline Doublet
A unique doublet displaying a yellowish chatoyant sheen is examined by the Tokyo lab.

Gray Spinel: A New Trend in Colored Stones
In recent years, the colored stone world has seen a growing appetite for unusual colors.
Colombian Emeralds and Mozambican Rubies from Fura Gems
An update on activity at the Coscuez emerald source, as well as ruby deposits in Mozambique.
Low-Fe, High-V Color-Change Burmese Sapphire
The Carlsbad lab identifies a color-change Burmese sapphire with a unique chemistry profile.
Provenance Discrimination of Freshwater Pearls by LA-ICP-MS and Linear Discriminant Analysis (LDA)
Investigates trace-element chemistry of freshwater natural pearls from North America and China with LA-ICP-MS and uses LDA to identify their origins.
Lazurite in Spinel
Spinel is often inclusion free but occasionally showcases unusual inclusions.
Largest Square Cushion-Cut Tsavorite
A 283.74 ct rough tsavorite from Merelani, Tanzania, yields a square cushion-cut gemstone weighing 116.76 ct.
Hackmanite/Sodalite from Myanmar and Afghanistan
Significant amounts of gem-quality sodalite/hackmanite—some unusually transparent—have been produced.
Boulder Opal Mining with Rod Griffin (英語)
At the AGTA show, Rod Griffin (Rod Griffin Boulder Opals, Silverado, California, and Queensland, Australia) told us that the world market for all types of opals continues to be strong, but Australia’s opal industry is shrinking due to the costs, challenges, and changing regulations of mining.
Second Annual Buccellati Award Winner
A graduate of GIA’s Jewelry Design program in Taiwan is the recipient of the Buccellati Award.
Large Faceted Gahnospinel
Advanced testing helps to identify the largest gahnospinel seen at any GIA laboratory.
U-Pb Ages of Zircon Inclusions in Sapphires from Ratnapura and Balangoda (Sri Lanka) and Implications for Geographic Origin
Establishes a metamorphic origin for sapphire samples from these deposits, supported by their trace-element composition and inclusion characterization, including the age dating of zircon inclusions.
Pleochroism and Color Change in Faceted Alexandrite: Influence of Cut and Sample Orientation
Shows how alexandrite’s color and color change are affected by cut and the orientation of table facets.
Sourcing Stones with Columbia Gem House
Thoughts from a longtime Tucson exhibitor on responsible practices and the changing market trends.
The Rock Hound: Muzo Emeralds and Ethical Practices
Susi Smither discusses her sustainable, responsible, and ethically based business practices.

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