Clinotobermorite

Formula:  Ca₅Si₆(O,OH)₁₈ ^. 5H₂O

Origin of name:  From monoclinic and tobermorite

Crystal system:  Monoclinic

Crystal class:  m or 2/m

Twinning: On {001} or along [100], well developed polysynthetic on a microscopic scale

Unit cell: a = 11.331, b = 7.353, c = 22.67, β = 96.59°

Colour:  Colourless to white

Diaphaneity:  Transparent

Luster:  Vitreous

Habit:  Platy crystals to 3 mm, acicular

Hardness:  4.5

Specific gravity:  2.58

Cleavage:  2; {001} perfect, {100} poor

Tenacity:

Streak: White

Synonyms/varieties:

Comments:  Dimorphous  with tobermorite