Gemstones
Spinel: The Great Imitator's Own Gem
For centuries spinel was mistaken for ruby and sapphire in crown jewels; today it is prized in its own right for strong colour and rarity in larger sizes.
A history of mistaken identity
Famous 'rubies' in historic crown jewels, including gems in the British Crown Jewels, were later identified as red spinel, a separate mineral species that can closely resemble corundum.
Colour range and rarity
Spinel occurs in red, pink, blue, purple and orange. Fine red and vivid blue (sometimes called cobalt) spinels in larger sizes are genuinely rare and increasingly sought by collectors.
Typically untreated
Most spinel on the market is untreated, which, combined with good hardness around 7.5–8 Mohs, makes it an appealing and honest alternative to more heavily treated coloured stones.
Buyer checklist
- ✓ Ask whether the stone is untreated, as is common for spinel
- ✓ Request a lab report for cobalt-blue spinel given rarity and value
- ✓ Compare pricing against ruby or sapphire alternatives in the same hue
Verification tools & references
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