Gem Reference
Gem Reference
Blue spinel runs from affordable steely grey-blue to the electrifying, extremely rare cobalt blue — a singly refractive sapphire alternative with its own collector market.
Sign in to unlock price ranges by tier, common misidentifications, diagnostic inclusions, treatments, spectra, trade names and sources — free with the GT200 Gem Identification course.
GT200 Gem Identification ↗ Sign inBrowse the free gem reference · Test your eye — the Great Gem Quiz · Singapore gem testing labs
