Ashburtonite

Formula:  Pb₄Cu₄HSi₄O₁₂(HCO₃)₄(OH)₄Cl

Origin of name:  After locality; Ashburton Downs pastoral lease and homestead, Western Australia

Crystal system:  Tetragonal

Crystal class:  4/m

Twinning:

Unit cell: a = 14.1852 Å, c = 6.0759 Å

Colour:  Blue with greenish tint

Diaphaneity: Transparent

Luster:  Vitreous

Habit:  Tiny prismatic crystals to 30 x 400 um in aggregates to 20 mm

Hardness: 

Specific gravity:  above 4.07

Cleavage:  None

Tenacity: Brittle

Streak:  Pale blue

Synonyms/varieties:

Comments: Found in weathered shear zone cutting shales and graywackes, as an alteration of galena and probably chalcopyrite