Graphite

Introduction: The Greeks used graphite as a crayon thousands of years ago and called it graphein, meaning 'to write'. Platy crystals are usually black to silvery-black. The main use is for pencil lead as well as brake linings, batteries, refractory bricks and carbon brushes.

Distribution: The metamorphic rocks 20km south-west of Otjiwarongo contain small flakes of graphite. A graphite mine did operate 60km east of Aus.

Composition: Native element

Crystal system: Hexagonal

Lustre: Metallic, dull, earthy

Streak: Black

Hardness: 1-2