Dumortierite

Introduction: A lump of dumortierite is normally an enormous, blue-violet-purple rock, usually cut for ornamental purposes. It is named after a French palaeontologist, Eugene Dumortier.

Distribution: North of the Erongo Mountains on farm Etemba 135 west of Omaruru. Also found from the farm Carolina 99 in the Keetmanshoop region.

Composition: Silicate

Crystal system: Orthorhombic

Lustre: Dull, vitreous

Streak: White

Hardness: 8.5