Hechtsbergite

Formula: Bi₂VO₅OH

Origin of name: Named after the locality, Hechtsberg quarry at Hausach, Black Forest, Germany

Crystal system: Monoclinic

Crystal class: 2/m

Twinning: 

Unit cell: a = 6.791, b = 7.535, c = 10.881, β = 107°

Colour: Brown

Diaphaneity: Transparent to translucent

Luster: Adamantine

Habit: Euhedral

Hardness: 4.5

Specific gravity: 6.87

Cleavage: None

Tenacity: Conchoidal fracture

Streak: Yellow

Synonyms/varieties:

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