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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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Buyer's Guide

Spinel has been making a name for itself over the last couple of decades, and demand exceeds supply. Spinel comes in a variety of colors, but the most commercially important are red and pink.


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What To Look For

Tanzanian Spinel
The most valued colors are vivid reds and blues.

The most valued spinel colors are the vivid reds and cobalt blues that remind us why spinel was once confused with ruby and sapphire. Although the most commercially important colors are red and pink, mauve- or lilac-colored gems are also attractive, and some blue spinel colors can be very valuable.

Clarity Refers To The Inclusions

Pastel colors of spinel are expected to be relatively free of inclusions but saturated reds and blues are rare, so some inclusions are expected. Some gems have beautiful inclusions that reflect the gem’s octahedral crystal growth. They might appear in groups that resemble human fingerprints.

“Rose Red” Spinel
Cut is one of the most important factors in appearance.

Spinel is most often cut in cushion and oval shapes. When properly proportioned it has excellent brilliance. Because of the scarcity of spinel on the market, most fine-quality rough is cut in non-standard sizes to save weight, instead of in standard industry sizes.

Carat Weight Allows For Precise Measurements

Although the spinels of history are impressively large, this gem is rare in sizes above five carats today. Standard-cut, or calibrated, stones are available, usually in 6×4-mm and 7×5-mm sizes, suitable for center stones in rings. Commercial qualities are more commonly cut to standard sizes for jewelry.

Spinel Quality Factors: The Comprehensive Guide

Tips & Advice

1. Understand the difference that color makes.

Look at different colors of spinel side by side to understand the range of qualities available. Pale colors are more affordable than vivid shades.

2. Don’t compromise on cut.

The quality of the cut can make a big difference in beauty and brilliance. Your spinel should sparkle in a lively way, reflecting light back evenly across the entire gem. Poorly cut gems are much less marketable and sell at a discount.

3. Work with a knowledgeable jeweler.

Because spinel is an unusual gem, make sure you choose a jeweler who has gemological knowledge and expertise.

4. When in doubt, get a lab report.

For a significant purchase, consider a report from an independent laboratory like GIA to confirm that the spinel you are buying is natural.