Koenenite

Formula:  Na₄Mg₉Al₄Cl₁₂(OH)₂₂

Origin of name:  For A. von Koenen, German geologist

Crystal system:  Hexagonal

Crystal class:  -3

Twinning: 

Unit cell: 

Colour:  Colourless; pale yellow to dark red due to inclusions

Diaphaneity:  Transparent to translucent

Luster:  Pearly on cleavage

Habit:  Crystals indistinct in crusts; rosettes of tablets

Hardness:  ~ 1.5

Specific gravity:  1.98

Cleavage:  1; {0001} perfect

Tenacity: 

Streak: 

Synonyms/varieties:

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