Spinel is a good candidate for the title of “History’s Most Under-Appreciated Gem.” Some ancient mines that supplied gems for royal courts from Rome to China produced spinels, but they were usually confused with better-known stones like ruby and sapphire.

Some of the world’s most illustrious “rubies” are actually spinels. One of these is the Black Prince’s Ruby, a polished but unfaceted red spinel that weighs about 170 cts. It appears in historical records dating back to the 1300s and is a central stone in the British Imperial State Crown.

Modern technology hasn’t helped spinel’s confused identity, either—at least, as far as the general public is concerned. This is largely due to the widespread use of synthetic spinel as an imitation for many other gems. Most customers don’t even know there’s a natural version of the stone.

Limited availability also contributes to spinel’s lack of public recogni­tion. Gem-quality material is typically transparent and faceted, but it’s hard to find in sizes larger than 5 cts.

Spinel’s color range includes violet, blue, orange, red, pink, and purple. Blue spinels are often grayish and subdued, but the best are a deep rich color. The reds can rival fine ruby. And the vivid orange to orange-red stones merit their trade name—flame spinel. Some spinels show color-change, usually turning from grayish blue in daylight or fluorescent light to purple under incandes­cent light.

In addition to its attractive colors, spinel is a hard, tough stone that’s suitable for daily wear in any type of jewelry. It will always be popular with customers who like beautiful and unusual gems.

Sources
Spinels have been found in Cambodia, Myanmar (Burma) -known for fine-quality pink and red spinels, Sri Lanka, Tanzania, and Thailand.

Hardness & Toughness
Spinel has a hardness of 8 on the Mohs scale, and good toughness.

Stability
Spinel is stable to light and chemicals, but high heat may cause the color to fade.

Care and Cleaning
Spinel can be cleaned in warm, soapy water.  Steam and ultrasonic cleaning are usually safe.

Imitations
Glass, synthetic ruby, and synthetic sapphire have been used to imitate spinel.

Synthetics
Synthetic spinels are commonly created using the flame fusion and flux methods.

 

Text from GIA's Essential Colored Stone Reference Guide ©GIA 1999