Margarite

Formula:  CaAl₂(Al₂Si₂)O₁₀(OH)₂

Origin of name:  From Greek for pearl

Crystal system:  Monoclinic

Crystal class:  m

Twinning: 

Unit cell: 

Colour:  Greyish pink, pinkish pale yellow, pale green

Diaphaneity:  Translucent

Luster:  Pearly

Habit:  Crystals tabular, pseudohexagonal, rare; platy aggregates; scaly masses

Hardness:  3.5 to 4.5

Specific gravity:  3.0 to 3.1

Cleavage:  1; {001} perfect

Tenacity: 

Streak:  Colourless

Synonyms/varieties:

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