Tienshanite

Formula: BaNa₂MnTiB₂Si₆O₂₀

Origin of name: after locality Tien-Shan, Tadzhikistan

Crystal system: Hexagonal

Crystal class: 6/m

Twinning:

Unit cell: a = 16.772, c = 10.435

Colour: Pistachio green

Diaphaneity: Transparent to translucent

Luster: Vitreous

Habit: massive, finely crystalline aggregates, to 6 cm

Hardness: 6 to 6.5

Specific gravity: 3.29

Cleavage: 1; {0001} distinct

Tenacity: Brittle

Streak: 

Synonyms/varieties:

Comments:  Found in pegmatite cutting alkalic syenite.