Aerinite

Formula: Ca₄(Al, Fe, Mg)₁₀Si₁₂ O₃₆ (OH)₁₂ (CO₃)^. 12H₂O

Origin of name:  from Greek for sky blue, referring to its colour

Crystal system:  Monoclinic

Crystal class:  Unknown

Twinning:

Unit cell: a = 14.690 Å, b = 16.872 Å, c = 5.170 Å, b = 94°45'

Colour:  Blue, blue-green

Diaphaneity: Translucent to semitransparant

Luster: Vitreous

Habit:  Fibrous

Hardness:  3

Specific gravity:  2.48

Cleavage:  None

Tenacity:

Streak: Bluish White

Synonyms/varieties:

Comments: A hydrothermal mineral of the zeolite facies, formed at relatively low temperature in fractures cutting mafic igneous rocks