Spinel · August birthstone
Spinel
The stone that was mistaken for ruby in crown jewels, and is finally priced on its own.
- Hardness
- Mohs 8
- Toughness
- Good
- Daily wear
- Excellent for daily rings
- Price tier
- USD 300 to 5,000 (cobalt blue and fine red higher) per carat, fine quality
- Colours
- Red, Hot pink, Cobalt blue, Grey, Lavender
- Origins
- Myanmar, Vietnam, Tanzania, Sri Lanka, Tajikistan
Spinel is a hard, bright magnesium aluminium oxide that forms alongside ruby and sapphire and was confused with them for centuries; the Black Prince’s Ruby in the British crown is a spinel. Red and hot-pink spinels from Myanmar and Tanzania, cobalt-blue spinel from Vietnam and elegant grey spinels are now sought after in their own right. Almost never treated, hard enough for daily wear.
How to buy spinel
Red and cobalt blue command the highest prices; pink, lavender and grey are excellent value. Buy for brightness; spinel is singly refractive and looks clean and lively when well cut.
Treatments
Almost never treated.
Care
Warm soapy water; ultrasonic is safe.
Lore
Several famous historic rubies, including the Timur Ruby, turned out to be spinels once gemology could tell the difference.
