The Talisman of Charlemagne: New Historical and Gemological Discoveries
Reveals new details about this historical jewel and the results of its first gemological analysis.
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.
Land of Origins: A Gemological Expedition to Ethiopia
Documents a visit to the sapphire, opal, and emerald mining and trading areas of Ethiopia.
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.
Recycled Gemstones from Perpetuum Jewels
A wholesaler supplying the bridal market with recycled gemstones and antique cuts shares his thoughts on the market and on responsible practices.
CIBJO Blue Book and “Do’s and Don’ts” Guide on Responsible Sourcing
The World Jewellery Confederation (CIBJO) released the first edition of the Responsible Sourcing Book in January 2019.
Trapiche-Like Ruby from the Batakundi Mine, Kashmir
Trapiche-like ruby from Kashmir shows a well-formed fixed six-rayed pattern.
Appendix 3: Calculation Method for Tourmaline Species Classification Used Here
Appendix 2: Comparison of LA-ICP-MS and EPMA Data, Part 2
Native Copper Inclusions in Indonesian Purple Chalcedony
Indonesian purple chalcedony containing interesting native copper inclusions is a first for the Carlsbad lab.
CVD Layer Grown on Natural Diamond
A composite of synthetically grown and natural diamond was recently identified by the Carlsbad laboratory.
Diamonds from the Deep: How Old Are Diamonds? Are They Forever?
The age of something is fundamental. Humans, animals, wine, cars, and antiques are viewed and understood in the context of their age.
Trapiche Emerald from Colombia
The examination of a nearly complete trapiche emerald crystal–which are difficult to obtain–is consistent with the findings of previous studies.
“Rainbow Lattice” from Australia
One of the most striking materials encountered in the Riverpark Inn (Pueblo) Gem Show was “rainbow lattice.”
Appendix 1: Comparison of LA-ICP-MS and EPMA Data, Part 1
Appendix 5: Simplified Tourmaline Species Classification for LA-ICP-MS Data
Appendix 4: Guideline for Simplified Distribution of Site Occupancy for LA-ICP-MS Data
Sourcing Stones with Columbia Gem House
Thoughts from a longtime Tucson exhibitor on responsible practices and the changing market trends.
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