Gyrolite

Formula:  NaCa₁₆(Si₂₃Al)O₆₀(OH)₅ ^. 15H₂O

Origin of name:   From Greek for round

Crystal system:  Triclinic

Crystal class:  -1

Twinning:  About axis perpendicular to {001}

Unit cell: a = 9.72 Ǻ, b = 9.72 Ǻ, c = 22.40 Ǻ, α = 95.7°, β = 91.5°, γ = 120.0°

Colour:  Colourless, white

Diaphaneity:

Luster:  Vitreous

Habit:  Massive, lamellar-radiate structure; concretionary

Hardness:  3 to 4

Specific gravity:   2.34 to 2.45

Cleavage:  1; {001} perfect

Tenacity:  Uneven; brittle

Streak: 

Synonyms/varieties:

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