Adamantine spar is a silky brown variety of corundum. It has a hardness of 9 on the Mohs scale.
See also
- Yogo sapphire
Adamantine spar
27 words updated Jun 18, 2026, 1:08 PM
WikiHQWikiHQ27 words updated Jun 18, 2026, 1:08 PM
Adamantine spar is a silky brown variety of corundum. It has a hardness of 9 on the Mohs scale.