Levyne

Formula:  (Ca,Na₂,K₂)Al₂Si₄O₁₂ ^. 6H₂O

Origin of name:  For Armand Lévy, French mathematician

Crystal system:  Hexagonal

Crystal class:  -3 2/m

Twinning:  Universal on {0001}, penetration

Unit cell: a = 13.36 Å, c = 22.88 Å

Colour:  Colourless, white, grayish, tinted yellowish or reddish

Diaphaneity: 

Luster:  Vitreous

Habit:  Crystals thin tabular; sheaf-like aggregates

Hardness:  4 to 4.5

Specific gravity:  2.09 to 2.16

Cleavage:  None

Tenacity:  Uneven; brittle

Streak:  White

Synonyms/varieties:  Levynite

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