Adamantine spar explained

Adamantine spar is a silky brown variety of corundum. It has a hardness of 9 on the Mohs scale.^[1]

See also

• Yogo sapphire

Notes and References

1. Web site: Adamantine Spar . September 15, 2007 . https://web.archive.org/web/20071018072823/http://www.mindat.org/min-5135.html. 18 October 2007 . live.