Gems & Gemology at Ninety: Consistency and Change
An overview of the Summer 2024 Gems & Gemology content.
Blister Pearl vs. Shell Blister from Pteria sterna
GIA’s Mumbai laboratory reports on the study of Pteria sterna shells with visible protuberances.
Seed Features in an Akoya Keshi Pearl
Examination of an akoya keshi pearl in the Mumbai laboratory reveals rare seed features and an acicular structure.
Graphite in Sapphire
A three-phase fluid inclusion containing graphite is observed in a Sri Lakan sapphire.
“Ruffles” on a Freshwater Pearl
A rainbow-colored wavy pattern is revealed under the surface of a non-bead cultured freshwater pearl.
Sapphire Displaying Tire Tracks in Snow
Particle clouds close to the surface of a blue sapphire create a scene reminiscent of tire tracks in snow.
Fascinating Snakeskin Pattern on a Pen Shell
A pen shell examined in GIA’s Mumbai laboratory exhibits a pattern resembling the skin of a snake.
Transparent Spinel Inclusion in Pink Sapphire
A pink sapphire from Mogok hosts a large surface-reaching spinel inclusion.
Star of David Pattern in Vietnamese Sapphire
A Star of David pattern is observed within partially healed fissures in a sapphire from southern Vietnam.
Bicolor Chrysoberyl with Chrysoberyl and Alexandrite Zones
The Tokyo laboratory reports on a submitted stone composed of both chrysoberyl and alexandrite.
Calcite Pearl with Red X-Ray Fluorescence
A nacreous-looking calcite pearl exhibiting red X-ray fluorescence is documented for the first time at GIA.
Large Treated-Color CVD Laboratory-Grown Diamond Rings
Testing of five CVD laboratory-grown diamonds submitted to the New York laboratory reveals post-growth treatment to achieve fancy colors.
Large Tridacna Shell with a Blister Pearl and a Shell Blister
A large shell submitted to the Mumbai laboratory exhibits both a blister pearl and a shell blister.
Neptunite Inclusions in Rare Poudretteite
The first recorded occurrence of neptunite inclusions in poudretteite.
Diffusion-Induced Blue Spinel-Like Layer on Natural Sapphire
Three natural sapphires exhibiting a surface layer of gahnite are studied at the GGTL laboratory.
Laboratory Growth of Gem Materials and the Attempt to Replicate Nature
Provides an overview of processes for synthesizing gem materials and explains how unique growth conditions enable them to be separated from naturally formed gems.
An “Eye” on a Tridacninae Pearl
A Tridacninae pearl exhibits a flame structure resembling an eye.
“Snail” in Diamond
While different types of inclusions often occur independently within diamond, it is quite rare to find more than one occurring simultaneously, let alone in contact with each other.
Portrait of a Paraíba Rough: Challenging Gems in Hard Times
Many variables were involved in the sale and manufacture of a beautiful rough gem during difficult times.
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