Yanomamite

Formula: InAsO₄.2H₂O

Origin of name: for Yanomani people of the Amazon basin, Brazil

Crystal system: Orthorhombic

Crystal class: 2/m 2/m 2/m

Twinning:

Unit cell: a = 10.446, b = 9.085, c = 10.345

Colour: Pale green to yellow-green, blue green

Diaphaneity: Transparent

Luster: Vitreous, waxy

Habit: Euhedral dipyramidal crystals up to 0.2 mm

Hardness: 5.5-6

Specific gravity:  3.87

Cleavage: 1, Indistinct

Tenacity: 

Streak: White

Synonyms/varieties:

Comments: soluble in strong HCl and H₂SO₄, crystals always coated with film of scorodite