Individual Spinel Gem Crystals For Sale In 4x Lens Lid Magnifying Box

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(4)is a Magnesium and Aluminium Oxide mineral with a cubic crystal system, a Mohs scale hardness of 7.5-8, and a specific gravity of 3.58-4.4. It was only in 1783 that a clear distinction was made between gem grade red corundum and gem grade red spinel, before then, both were refered to as 'rubies'.

5 GBP