Barbertonite

Formula:  Mg₆Cr₂(CO₃)(OH)₁₆ ^. 4H₂O

Origin of name:  After locality; Barberton district, Transvaal, South Africa

Crystal system:  Hexagonal

Crystal class:  6/m 2/m 2/m

Twinning:

Unit cell:

Colour:  Deep lilac to rose-pink

Diaphaneity:  Translucent to transparent

Luster:  Pearly to waxy

Habit:  Massive; matted or twisted masses of fibres or flattened plates; cross-fibre veinlets

Hardness:  1.5 to 2

Specific gravity:  2.1

Cleavage:  1; {0001} perfect

Tenacity:

Streak:  White to pale lilac

Synonyms/varieties:

Comments:  Dimorphous with stichtite