Arsenogorceixite

Formula:  BaAl₃(AsO₄)(AsO₃OH)₂(OH)₆

Origin of name:  From arsenic and relation to gorceixite

Crystal system:  Hexagonal

Crystal class:  -3 2/m

Twinning:

Unit cell: a = 7.10 Å, c = 17.39 Å

Colour:  White to yellow, bluish, colourless

Diaphaneity: Translucent to transparent

Luster:  Vitreous

Habit:  Tabular crystals, pseudo-octahedral crystals, radiating crystals forming spherulitic aggregates

Hardness:  4

Specific gravity:  3.65

Cleavage:  None

Tenacity:

Streak:  White

Synonyms/varieties: Weilerite

Comments:  Arsenate analogue of gorceixite. Member of the crandallite group. Found as a rare secondary mineral in the oxidised zone of a hydrothermal polymetallic barite-fluorite deposit.