Spinel
| Property | Details |
|---|
| Mineral | Spinel |
| Mohs Hardness | 8 |
| Refractive Index | 1.712 – 1.762 |
| Birthstone | August (alternative) |
| Major Sources | Myanmar, Sri Lanka, Tanzania, Vietnam, Tajikistan |
| Treatments | Rarely treated (a key selling point) |
Overview
Spinel is one of the most underappreciated gemstones in the jewelry world, despite a long history of being mistaken for ruby and sapphire. The famous Black Prince's Ruby in the British Crown Jewels is actually a red spinel. The Timur Ruby, a 352-carat stone owned by Queen Elizabeth II, is also spinel. Spinel comes in a stunning range of colors, including vivid red, hot pink, cobalt blue, lavender, and orange.
Why Collectors Love Spinel
Unlike most gemstones, fine spinel is rarely treated—the color you see is typically entirely natural. This appeals enormously to gem purists and collectors who value untreated natural gems. Red and cobalt blue spinels are the most valuable and can rival fine rubies and sapphires in beauty and price. Spinel also has excellent durability at 8 on the Mohs scale, has no cleavage, and is tough enough for any type of jewelry.
Color Varieties
Red spinel: Vivid red, sometimes called balas ruby. The finest rival pigeon blood rubies. Cobalt blue spinel: An electric, vivid blue caused by cobalt. Extremely rare and valuable. Pink spinel: Hot pink to pastel pink, very popular and more affordable. Lavender spinel: Soft purple to violet. Flame spinel: Vivid orange from Tanzania. Gahnite: Blue-to-green zinc spinel.
Care & Cleaning
Spinel ranks 8 on the Mohs scale, making it very durable for rings and everyday jewelry. It can be cleaned safely with warm soapy water, ultrasonic cleaners, or steam cleaners. An excellent and still undervalued alternative to ruby and sapphire.
Frequently Asked Questions
What is the Black Prince's Ruby?
The Black Prince's Ruby is a famous 170-carat red gemstone set in the British Imperial State Crown. Despite its name, it is not a ruby but a red spinel. It has been in the possession of English monarchs since 1367 and has survived numerous battles and near-disasters. The stone is uncut and polished in the old style, and its true identity as spinel was only confirmed in the modern era when gemological testing became available.
Why is spinel considered undervalued?
Spinel has been undervalued for decades primarily because of confusion with synthetic spinel, which was widely used as a cheap simulant in costume jewelry during the 20th century. Many consumers associated the name spinel with fake gems, not realizing that natural spinel is a rare and beautiful gemstone in its own right. As gem education improves and collectors discover spinel's beauty, rarity, and untreated nature, prices have been rising steadily, particularly for red and cobalt blue varieties.
Is spinel treated or enhanced?
One of spinel's greatest selling points is that it is almost never treated. The vivid colors you see in natural spinel are entirely produced by nature, without heat treatment, irradiation, or any other enhancement. This is exceptionally rare among colored gemstones. For comparison, the vast majority of rubies and sapphires are heat-treated. Spinel's untreated nature makes it especially appealing to collectors and gem purists.
What is cobalt blue spinel?
Cobalt blue spinel is an extremely rare variety colored by cobalt, producing an intense, electric blue that is unlike any other gemstone. The finest cobalt blue spinels come from Vietnam, Sri Lanka, and Tanzania. They are among the most valuable spinels, with top specimens exceeding $10,000 per carat. The cobalt origin of the color can be confirmed through spectroscopic testing, and certified cobalt blue spinels command significant premiums.
How does spinel compare to ruby and sapphire?
Spinel, ruby, and sapphire are often found together in the same geological deposits. Red spinel can closely resemble ruby, and blue spinel can look like sapphire. Spinel is slightly softer (Mohs 8 vs 9) but still very durable. The key advantages of spinel are its untreated nature and lower price point. The key advantages of ruby and sapphire are their greater hardness and established market recognition. For gem enthusiasts, spinel offers comparable beauty at a more accessible price.
Specialty & Collector Gemstones