Planchéite

Formula: Cu₈Si₈O₂₂(OH)₄.H₂O

Origin of name: for Mr. Planché, French explorer

Crystal system: orthorhombic

Crystal class: 2/m 2/m 2/m

Twinning: 

Unit cell: a = 19.04 Å, b = 20.13 Å, c = 5.269 Å

Colour: light to dark blue

Diaphaneity: 

Luster: satiny

Habit: fibrous, compact radial aggregates

Hardness: 5.5

Specific gravity: 3.65 to 3.80

Cleavage: none

Tenacity: 

Streak: 

Synonyms/varieties:

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