Pinctada radiata Atypical Bead Cultured Pearls from the UAE
GIA’s Mumbai laboratory reports on pearl samples from a culturing experiment by the Suwaidi Pearl Farm in the UAE.
Quarterly Crystal: Columbite(?) in Beryl
Examination of a gem-quality aquamarine crystal reveals an inclusion cluster presumed to be columbite.
Morphology of Colombian Emerald: Some Less-Common Cases and Their Growth and Dissolution History
Evaluates the growth mechanisms of special morphological features in Colombian emerald, including possible relationships to trapiche emeralds and samples displaying the gota de aceite effect.
CVD Diamond Over 34 Carats Examined in GIA’s Hong Kong Laboratory
A look at the largest CVD diamond GIA has encountered to date.
Color Modification of Spinel by Nickel (Ni) Diffusion: A New Treatment in the Gem Market
GIA researchers report on a new nickel-diffusion treatment used to modify color in spinel and present criteria for identification.
Fall 2022 Auction Highlights
A successful spring season set high expectations for colored diamonds at auction in late 2022.
Omphacite in Pink Diamond
A bluish green omphacite crystal is discovered in a Fancy brown-pink diamond.
“Electromagnetic Wave” Inclusion in Mong Hsu Ruby
Fiber-optic illumination reveals an electromagnetic wave-like pattern of particles in a ruby from Myanmar.
Two Black Non-Nacreous Bead Cultured Pearls from Pinctada margaritifera
Four-Rayed Star Chrysoberyl
An Extraordinarily Large Cat’s-Eye Emerald
The Tokyo laboratory examines a 126 ct cat’s-eye emerald from Brazil.
Extremely Rare Hellandite Inclusion Found in a Mogok Ruby
A rare inclusion is reported in ruby from the Mogok mine for the first time.
Low-Temperature Heating of Mogok Ruby, Copper-Diffused Feldspar, Porcelain-Treated Turquoise, and the Work of Gem Artist Chi Huynh
Gems Formed in Magmatic Rocks
This installment of “Colored Stones Unearthed” covers gemstones that formed in magmatic environments and the insights they offer into the evolution of the earth and the geological processes that shaped our world.
Composition and Spectral Characteristics of Porcelain-Treated Turquoise
Characterizes turquoise treated with an inorganic additive that dramatically improves the luster and color of low- and medium-quality material.
Never Stop Innovating: Gem Artist Chi Huynh
Profiles a groundbreaking gem artist on a quest to bring new concepts, techniques, and products to the industry.
A Canary in the Ruby Mine: Low-Temperature Heat Treatment Experiments on Burmese Ruby
Documents heating experiments conducted on Burmese rubies to find useful indicators of heat treatment at temperatures below 1200°C.
Unusual “Horsetail” and Columnar Inclusions in Demantoid
Examination of a yellowish green demantoid reveals fibers of serpentine in a randomly curved pattern and a columnar two-phase negative crystal.
A Partially Hollow Natural Blister Pearl Filled with Foreign Materials
A very large baroque white pearl is further examined in the Mumbai laboratory due to its suspicious heft.
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