The Anahí Ametrine Mine, Bolivia
The Anahí mine, Bolivia, has produced large amounts of amethyst, citrine, and amethyst-citrine for the gem market.
The Talisman of Charlemagne: New Historical and Gemological Discoveries
Reveals new details about this historical jewel and the results of its first gemological analysis.
Applications of Laser Ablation–Inductively Coupled Plasma–Mass Spectrometry (LA-ICP-MS) To Gemology
Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) is an important technique for quantitative chemical analysis.
“Paraíba”-Type Copper-Bearing Tourmaline from Brazil, Nigeria, and Mozambique: Chemical Fingerprinting By LA-ICP-MS
Gem-quality bright blue to green “Paraíba”-type Cu-bearing tourmaline is now known from deposits in Africa (Nigeria and Mozambique), in addition to three commercial localities in Brazil (in Paraíba and Rio Grande do Norte States).
Turquoise from Zhushan County, Hubei Province, China
A relatively new source of gem-quality turquoise is hosted within slates in Zhushan County of China’s Hubei Province.
Solution-Generated Pink Color Surrounding Growth Tubes and Cracks in Blue to Blue-Green Copper-Bearing Tourmalines from Mozambique
Several transparent, faceted, blue to blue-green copper-bearing tourmalines containing growth tubes and cracks surrounded by sleeves of pink color were examined for this report.
Characterization of Peridot from Sardinia, Italy
Gem-quality peridot is occasionally found as mantle xenoliths within basalts near Pozzomaggiore.
The Yogo Sapphire Deposit
Yogo Gulch, discovered more than 100 years ago, is one of four major sapphire-producing areas in Montana, United States.
Geology and Development of the Lomonosov Deposit, Northwestern Russia
Reviews diamond discoveries at the Lomonosov deposit, as well as the geology of the Arkhangelsk kimberlite province.
The Grand Sapphire of Louis XIV and The Ruspoli Sapphire: Historical and Gemological Discoveries
Archival research and gemological characterization reveal the true story of this 135.74 ct blue sapphire from the French crown jewels.