Qilianshanite

Formula: NaHCO₃.H₃BO₃.2H₂O

Origin of name: after locality Qilian Mountains, China

Crystal system: Monoclinic

Crystal class: 2

Twinning: polysynthetic

Unit cell: a = 16.119, b = 6.928, c = 6.73, β = 100.46°

Colour: Colourless

Diaphaneity: Transparent

Luster: Vitreous

Habit: aggregates to 4 mm, or tabular or prismatic crystals to 2 mm, commonly in massive aggregates

Hardness: 2

Specific gravity: 1.706

Cleavage: 2; {100}, {010} perfect

Tenacity: 

Streak: White

Synonyms/varieties:

Comments:  Soluble in water