Texas Topaz, Slovak Opal, a Beryl Inclusions Chart, and More
An overview of the Winter 2023 Gems & Gemology content.
An Unusual Partially Non-Nacreous Pinctada radiata Natural Blister Pearl
A large Pinctada radiata natural blister pearl displays a unique reaction under long-wave ultraviolet light.
Seed Pearls in an Antique Indian-Style Headdress
GIA’s Mumbai laboratory analyzes seed pearls decorating an Indian-style headdress.
Tubular Feature in a Natural Pearl
Investigation of a tubular feature in a natural pearl reveals evidence of parasitic activity.
Exquisite Butterfly in Diamond
A crystal inclusion with a stress halo resembles a colorful butterfly in a 1.01 ct diamond.
Octahedral Gahnospinel Crystal in Sri Lankan Blue Sapphire
A rare octahedral gahnospinel crystal is observed in Sri Lankan sapphire.
Bohemian Garnets as Decorative Materials for Glass Vessels from the Late Sixteenth to Early Eighteenth Centuries
Examines a technique for setting cut garnets on glass objects, invented by Claudius vom Creutz of Nuremberg in the late sixteenth century.
Artisanal Diamond Mining: Addressing the Knowledge Gap
Diamonds for Peace conducts basic training on rough diamond grading for artisanal miners in Liberia.
Blue Amblygonite-Montebrasite from Rwanda
A report on a new blue variety of amblygonite-montebrasite from Rwanda.
FTIR Identification of Carbon Dioxide Fluids in Sapphire
FTIR spectroscopy shows that the existence of carbon dioxide gas bubbles in a negative crystal in sapphire is no longer proof of the absence of heat treatment.
Demantoid, Andradite, and Grossular from Mexico
A look at new gem material from the iridescent andradite deposit in Sonora, Mexico.
Pyritized Triceratops Fossils from South Dakota
A newfound dinosaur site in the Hell Creek Formation of South Dakota leads to the discovery of pyritized triceratops fossils.
Cricket Bat Diamond
A diamond shaped like a cricket bat is submitted to GIA’s Mumbai laboratory.
Unusual Large Nacreous Pen Pearls
A report on the identification of three large baroque pearls submitted to the Mumbai laboratory.
Rare Faceted Thomsonite
A colorless semitransparent thomsonite is examined in the Carlsbad laboratory.
Small Freshwater Bead Cultured Pearls
The Carlsbad laboratory reports on a strand of 78 light bluish gray pearls submitted for identification.
“Kaleidoscope” in Alexandrite
Pleochroic colors caused by cyclic twinning produce a kaleidoscope effect in alexandrite.
Pseudo-Icosahedral Pyrite in Colombian Emerald
A 2.88 ct Colombian emerald plays host to a metallic yellow pyrite crystal.
Quarterly Crystal: Hiddenite from Idaho
Sail-shaped etch features provide proof that a sample sold as aquamarine is actually a spodumene crystal.