Tamarugite

Formula: NaAl(SO₄)₂.6H₂O

Origin of name: after locality Tamarugal Pampa, Cerro Pintado, Tarapaca, Chile

Crystal system: Monoclinic

Crystal class: 2/m

Twinning: Reportedly polysynthetic

Unit cell: a = 7.353, b = 25.225, c = 6.097, β = 95.2°

Colour: Colourless

Diaphaneity: Transparent

Luster: Vitreous

Habit: Crystals thin tabular or short prismatic, massive, fine-grained or fibrous

Hardness: about 3

Specific gravity: 2.06

Cleavage: 1; {010} perfect

Tenacity: 

Streak: White

Synonyms/varieties:

Comments: soluble in water, sweet astringent taste