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Spinel
The Black Prince's Ruby. The Timur Ruby. For centuries, spinel, the great imposter, masqueraded as ruby in Europe's crown jewels.
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Research
Purple Gem Spinel from Vietnam and Afghanistan: Comparison of Trace Element Chemistry, Cause of Color, and Inclusions
Figure 1. The vivid colors seen in fine gem-quality spinel are derived from the mixing between multiple different chromophores in a range of ratios and concentrations, as in this fine 13.52 ct violetish purple spinel. Courtesy of the Dr. Edward J. Gübelin Collection. Photo by Robert Weldon/GIA.
Micro-Features of Spinel
Provides a visual guide to the internal features of natural, synthetic, and treated spinel, as well as inclusions of spinel in other gemstones.
Field Gemology: Building a Research Collection and Understanding the Development of Gem Deposits
With more than 90 field expeditions on six continents since 2008, GIA has accumulated over 22,000 colored stone reference samples. This extensive collection of colored stones with known origins supports GIA’s research on geographic origin determination.
Gemstones in the Era of the Taj Mahal and the Mughals
A look at the gem ornamentation of this landmark, as well as the jewels of the Mughal dynasty.
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.
Quarterly Crystal: Wurtzite Phantom in Quartz
For the first time, wurtzite is found as an inclusion in gem material.
Wollastonite in Devitrified Glass Imitating Horsetail Inclusions in Demantoid Garnet
A yellowish green specimen with horsetail-like inclusions is found to be glass rather than demantoid garnet.
Interview with a Kenyan Miner and Dealer
Miriam Kamau, owner of Mimo Gems Traders Ltd. in Nairobi, transformed from an office assistant to a dealer and miner to a representative of her country on the international stage of the colored gemstone trade.
Designs from Erica Courtney
Erica Courtney has been adorning Hollywood stars for the red carpet for decades. Her eye for color and bringing out a stone’s beauty are immediately apparent.
Rex Guo: The Science and Art of Recutting Fine Gemstones
Rex Guo describes how he sources and systematically recuts faceted stones to unlock their inner beauty.
Unheated and Unusual Colors
Margit Thorndal of Madagascar Imports offers her perspective on the colored stone market.
Fine Gems and Update from Myanmar
A look at top-quality gems and insight into a delegation’s visit to gem mines in Myanmar.
