What Is Black Spinel?

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Black spinel is gemstone that is relatively unknown to consumers because of its rarity. It is an opaque, jet-black version of the red spinel, a gemstone with brilliant sparkle that is often mistaken for a ruby.

Chemical Makeup

Black spinel is made of magnesium aluminum oxide or magnesium aluminate. With a rating of 8 on the Mohs scale of hardness -- 10 being the hardest -- black spinel is a durable gem that resists chips and scratches.

Name Derivation

The origin of the name spinel is unclear, but it is possibly derived from the Latin word “spina,” meaning thorn, perhaps due to the brilliant color of the red spinel or because of the sharp crystals that can be seen in some spinels.


Black spinel is thought to re-establish relationships, dispel sadness and protect the wearer, according to GemTradeNet.com, a website promoting the Thailand gemstone market.


The primary source of black spinel is Thailand, where it is known as “nin.” Other deposits of the stone have been found in Africa, Myanmar and Sri Lanka.

Use in Jewelry

Black spinel is most often cut into an oval, round or cushion cut. Its hardness makes it suitable for both moderately priced and fine jewelry.