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.
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 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.
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.
Extremely Rare Hellandite Inclusion Found in a Mogok Ruby
A rare inclusion is reported in ruby from the Mogok mine for the first time.
An Extraordinarily Large Cat’s-Eye Emerald
The Tokyo laboratory examines a 126 ct cat’s-eye emerald from Brazil.
“Electromagnetic Wave” Inclusion in Mong Hsu Ruby
Fiber-optic illumination reveals an electromagnetic wave-like pattern of particles in a ruby from Myanmar.
Fall 2022 Auction Highlights
A successful spring season set high expectations for colored diamonds at auction in late 2022.
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.
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.
Omphacite in Pink Diamond
A bluish green omphacite crystal is discovered in a Fancy brown-pink diamond.
Fall 2022 G&G Available Now
Cat’s-Eye Paraíba Tourmaline with Copper Inclusions
The Tokyo laboratory examines a Paraíba tourmaline with chatoyancy caused by copper inclusions.
Inaugural Turquoise United Conference
A report on the first-ever Turquoise United conference in Albuquerque, New Mexico.
Synthetic Sapphire with Rose Channels
Rose channels and twinning planes are observed in light purplish blue synthetic corundum.
Update from Mozambique’s Ruby Mines
A field gemology team from GIA provides an update on the ruby mining operations around Montepuez.
Methods and Challenges of Establishing the Geographic Origin of Diamonds
Examines the current available means of determining the geographic origin of gem-quality diamond, which are based largely on trace element and isotopic characteristics. For now, no method exists for determining the provenance of a random individual diamond.
Sapphire Beneath the Rich Black Soil of Muling, Northeastern China
A comprehensive look at the gemological features and advanced analysis of blue and fancy-color sapphire from the agricultural area of Muling, China.
The Liquids Lurking Inside Your Diamonds
Examines the variety of fluid inclusions contained within diamond, which reflect the natural processes that created and modified these gems deep within the earth’s mantle.
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