Stilbite

Introduction: Stilbite belongs to the zeolite group of minerals, identifiable by a distinctive pearly lustre, forming bowtie-shaped crystals or fan-like sprays. Stilbite comes from the Greek stilbein or 'to glitter or shine' or stilbe meaning 'mirror'. Another feature is its colour; white.

Distribution: Basalts that outcrop in the Grootberg Pass north of the Haub River, 90km east of Khorixas on the Sesfontein road are of a good quality

Composition: Silicate

Crystal system: Monoclinic and orthorhombic

Lustre: Pearly, vitreous

Streak: White

Hardness: 3.5-4