Okenite

Formula: Ca₁₀Si₁₈O₄₆.18H₂O

Origin of name: for L. Oken, German naturalist

Crystal system: triclinic

Crystal class: -1

Twinning: on {102} about [010] axis, lamellar

Unit cell: a = 9.80 Å, b = 7.29 Å, c = 21.97 Å, a = 87.46°, b = 72.9°, g = 112.6°

Colour: white, may have yellowish or bluish tint

Diaphaneity: transparent

Luster: vitreous to pearly

Habit: crystals acicular, blade-shaped, radiating aggregates, massive, fibrous-interlaced or compact

Hardness: 4.5 to 5

Specific gravity: 2.28

Cleavage: 1; {010} perfect

Tenacity: 

Streak: 

Synonyms/varieties:

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