Bystrite

Formula:  Ca(Na,K)₇Si₆Al₆O₂₄S_4.5 ^. H₂O

Origin of name:  After locality; Malo-Bystrinskoe deposit, Russia

Crystal system:  Hexagonal

Crystal class:  3m

Twinning:

Unit cell:

Colour:  Colourless to yellow

Diaphaneity:  Transparent

Luster:  Vitreous

Habit:  Tabular crystals to 5 mm, grains and aggregates

Hardness:  5

Specific gravity:  2.43

Cleavage:  2; Good {101-0}, pinacoidal weak

Tenacity:

Streak:

Synonyms/varieties:

Comments:  Readily soluble in dilute acids