Unique Star Sapphire with Transparent Core
Uncommon Parallel Color Zoning in a Chameleon Diamond
A diamond examined in the Carlsbad lab shows chameleon coloring in an unusual pattern.
Wollastonite in Devitrified Glass Imitating Horsetail Inclusions in Demantoid Garnet
Perettiite-(Y) and Tusionite Inclusions in Phenakite from Myanmar
Merelaniite Inclusions in Tanzanite
产自巴西的达碧兹紫水晶 (英语)
大批高温高压合成米粒钻中发现的一颗天然米粒钻 (英语)
Over the last decade, the production methods used to create synthetic diamond melee have improved substantially, along with the quality of the specimens themselves.
Cabochons Fashioned from the Shell of Crassostrea Virginica
Crassostrea virginica, the so-called Eastern or American oyster, is a commercial seafood widely distributed along the east coast of the United States to the Gulf of Mexico.
Quarterly Crystal: Wurtzite Phantom in Quartz
For the first time, wurtzite is found as an inclusion in gem material.
Three Irradiated CVD Synthetic Diamonds
Irradiated CVD-grown diamonds are examined in the Carlsbad lab.
Gemstones and Sustainable Development Knowledge Hub
Projects developed by the GemHub to benefit miners, cutters, and others involved in the gem and jewelry industry.
IAC Conference on Responsible Gold
Gold: Vortex, Virtues, and Values was hosted by Initiatives in Art and Culture (IAC) at Bohemian National Hall in New York City, April 12–13. Now in its eighth year, the conference has become an annual industry gathering for those looking to evaluate the market, discover exceptional work, and discuss key gold-related issues.
Twelve-Rayed Star Sapphire from Thailand
A black star sapphire produced from eastern Thailand, showing both golden and silver rays, is studied at GIA’s Bangkok lab.
Microlite Crystals in Topaz from Pakistan
Aesthetically pleasing inclusions are found in topaz from Pakistan’s Shigar Valley.
Star Spinel with Four and Six Rays
Lotus Gemology receives submissions of star stones on a regular basis, so when we first saw the specimen shown here, it appeared to be one among many of our usual stones to test.
15 Carat HPHT Synthetic Diamond
Beryl and Glass Assemblage Imitating Emerald
An unusual assembled stone is examined at GIA’s New York lab.
Two Natural “Horse Conch” Pearls
Rare pearls, along with their shell, are studied in the Hong Kong lab.
Large HPHT-Treated Blue Type IIb Diamond
A look at the color zoning exhibited by the largest HPHT-treated blue diamond graded by GIA.
Natural-Color Blue, Gray, and Violet Diamonds: Allure of the Deep
Summarizes data collected on more than 15,000 natural blue/gray/violet diamonds examined by GIA during the last decade and examines the mechanisms that produce this color range.

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