Spinel

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Spinel is a mineral group which produces some of the finest gemstones, yet it has never been accepted by the general public as a valuable adornment due to poor marketing. It has a hardness that is equal to topaz and is very durable. Historically all red gemstones were termed "ruby" - or carbunculus - and the 170 ct red stone in the British Imperial State Crown has always been referred to as the "Black Prince's Ruby", while only in recent history it has been identified as a red spinel.

Victorian bracelet circa 1880-90 with a suite of red spinel set in 14 karat rose gold.
Image courtesy of Lang Antiques

In antique jewelry one will hardly ever encounter spinel although the jewelers from days gone by may have used them as rubies or sapphires. It was in the second half of the 18th century that the distinction between spinel and ruby was made and the demand for these former "oriental rubies" declined, as did the price, in favor of "real" rubies. One will for that reason not find many spinels in antique jewelry from the Georgian period hitherto (although spinel is gaining in popularity in present times).

The different optical and physical properties should pose little problems for an experienced gemologist to distinguish between them.

Historically spinel has been mined in Myanmar (Mogok) and Tajikistan. Newer deposits of importance are in Tanzania and Vietnam.


Gemological information for spinel
Color All colors
Crystal Structure Cubic
Family Spinel
Refractive Index 1.714-1.75
Durability Very durable
Hardness 8
Treatments Synthetics
Country of origin Myanmar, Sri Lanka
Spinel care
Ultrasonic cleaning Usually safe
Steam cleaning Usually safe
Warm soapy water Safe
Chemical attack Stable
Light sensitivity Stable
Heat sensitivity May fade

Online G&G articles on spinel

Lang Antiques
Lang Antiques