Cavansite

Formula:  Ca(VO)Si₄O₁₀ ^. 4H₂O

Origin of name:  Combination of symbols of elements

Crystal system:  Orthorhombic

Crystal class:  2/m 2/m 2/m

Twinning:

Unit cell: a = 9.778 Ǻ, b = 13.67 Ǻ, c = 9.601 Ǻ

Colour:  Greenish blue, sky-blue

Diaphaneity:

Luster:  Vitreous

Habit:  Crystals prismatic, elongated; spherulitic rosettes

Hardness:  3 to 4

Specific gravity:  2.21 to 2.31

Cleavage:  1; {010} good

Tenacity:  Brittle

Streak:

Synonyms/varieties:

Comments:  Dimorphous with pentagonite