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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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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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Chromium

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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Tools

Research

Web-like fingerprint seen in a Vietnamese spinel.
An A-maze-ing Fingerprint in Spinel

A maze-like pattern is observed in spinel from Vietnam.

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Iridescent needles in a Vietnamese red spinel resemble a skyline.
Vietnamese Skyline

Red spinel from Vietnam features iridescent needles resembling a futuristic skyline.

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A 69.96 ct antique cushion-cut gray spinel by David Nassi.
Gray “Spinel Sisters”

Two rare gray spinel stones stand out at the AGTA show for their exceptional size, quality, and color.

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13.52 ct violetish purple spinel
Purple Gem Spinel from Vietnam and Afghanistan: Comparison of Trace Element Chemistry, Cause of Color, and Inclusions

A chemical and spectroscopic comparison of two purple gem spinel samples, one of them the first reported example of a spinel with a saturated purple color caused predominantly by chromium and cobalt.

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Spinel Suite with Rough Mineral Specimen
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.

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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.
Article
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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Fall 2019 Taj Mahal
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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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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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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