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.
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.
Chart: Inclusions in Natural, Synthetic, and Treated Diamond
Provides a visual guide to the internal features of natural, synthetic, and treated diamonds.
Sapphires from Australia
An overview of Australia's recent significance in the production of blue sapphire.
Chart: Inclusions in Natural, Synthetic, and Treated Ruby
Provides a visual guide to the internal features of natural, synthetic, and treated rubies.
Saltwater Pearls from the Pre- to Early Columbian Era: A Gemological and Radiocarbon Dating Study
Examines 85 saltwater natural pearls, reportedly harvested from the Caribbean islands off the coast of Venezuela during the early 16th century, to determine their age.
Synthetic Star Sapphires and Rubies Produced by Wiede’s Carbidwerk, Freyung, Germany
Details the process used by Wiede’s Carbidwerk to produce star synthetic corundum from the mid-1950s through the 1970s.
Characteristics of Gem-Quality By-Product Synthetic Zincite
Investigates the properties of synthetic zincite produced by industrial kilns in Poland.
Alluvial Sapphires from Montana: Inclusions, Geochemistry, and Indications of a Metasomatic Origin
Microscopic and chemical analysis may provide clues to the original source of Montana’s alluvial sapphires and help distinguish them from sapphires with overlapping properties.
Digital Photomicrography for Gemologists
A guide to capturing gem inclusion scenes using practical equipment and techniques and the appropriate image-refining software.