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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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Stunning Color

The finest red spinel colors are pure red to slightly purplish red hues of medium to medium-dark tone.

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Cut for Brilliance

Spinel is most often cut in cushion and oval shapes; when properly proportioned it has excellent brilliance.

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Like ruby, the color of red spinel is due to traces of chromium.

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Nature’s Perfection

Spinel belongs to the cubic crystal system and its characteristic crystal shape is an octahedron, which looks like two back-to-back pyramids.

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Perfect for Jewelry

Like ruby, spinel is found in alluvial deposits; it ranks 8 on the Mohs scale and has good toughness, making it a durable gem for jewelry.

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Collector’s Favorite

Well-formed spinel crystals are in high demand among mineral collectors.

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Field gemologists sort through gem gravel in Myanmar
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.

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A multi-diamond brooch.
2019 in Review: Diamond Trade Begins Recovery, Jewelry Retail Blooms Late, Extraordinary Auction Sales

2019: A year of ups and downs in the gem and jewelry industry, including diamonds, retail, auction sales and laboratory-grown diamonds.

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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.

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Six-rayed star in an untreated spinel.
Star Spinel with Four and Six Rays

A cabochon displaying asterism is found to be an untreated spinel with two different stars.

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A yellowish green glass with numerous wollastonite needles similar in appearance to the horsetail inclusions in demantoids.
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.

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Three-Sided Phantom in Quartz
Quarterly Crystal: Wurtzite Phantom in Quartz

For the first time, wurtzite is found as an inclusion in gem material.

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Colored stone pendants designed by Erica Courtney
Designs from Erica Courtney

Award-winning jewelry designer Erica Courtney presents four of her creations.

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Tsavorite garnet and red spinel from Miriam Kamau’s mining operation in Kenya
Interview with a Kenyan Miner and Dealer

Miriam Kamau relates how she became a prominent dealer and miner.

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The Geometeer, a synthetic ruby with a hybrid cut by Rex Guo.
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.

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Small unheated spinel and sapphire exhibited by Madagascar Imports
Unheated and Unusual Colors

Margit Thorndal of Madagascar Imports offers her perspective on the colored stone market.

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