Corondum

Introduction: Named after the Tamil 'kurundam' as varieties of this mineral such as ruby and sapphire were mined in India for hundreds of years. They are found in either 'boulder-variety' corundum or in well-shaped crystals varying in size from 1cm to 20cm. It is the second hardest mineral after diamond.

Distribution: Farms Harib 142, Hochveld 112 and Girtis 109 in the Karasberg District. Corundum also occurs in the Windhoek District on Kransnek 269 and Bethlehem 27. It is also found in various locations in Damaraland and the Precambrian rocks near Warmbad.

Composition: Oxide

Crystal system: Hexagonal

Lustre: Vitreous

Streak: White

Hardness: 9