Cavansite

Cavansite, whose name is derived from its chemical composition, calcium vanadium silicate, is a deep blue hydrous calcium vanadium phyllosilicate mineral, occurring as a secondary mineral in basaltic and andesitic rocks along with a variety of zeolite minerals. Discovered in 1967 in Malheur County, Oregon, cavansite is a relatively rare mineral. It is polymorphic with the even rarer mineral, pentagonite. It is most frequently found in Poona, India, in the Deccan Traps, a large igneous province.
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General Information:
 Chemical Formula:
Ca(VO)Si4O10·4(H2O)
 Composition:
(Molecular Weight = 451.42 gm)
Calcium 8.88 % Ca
Vanadium 11.28 % V 
Silicon 24.89 % Si
Hydrogen 1.79 % H 
Oxygen 53.16 % O 
 Empirical Formula:
CaV4+Si4O11·4(H2O)
 Environment:
Secondary mineralization in basalts and andesites.
 IMA Status:
Approved IMA 1967
 Locality:
Deccan trap basalts, Poona, India.
 Name Origin:
Named after its composition of calcium, vanadium, and silicon.
Physical Properties:
 Cleavage:
[010] Good
 Color:
greenish blue or dark blue.
 Density:
2.21 - 2.31, Average = 2.25
 Diaphaniety:
Subtransparent
 Hardness:
3-4 - Calcite-Fluorite
 Luster:
Vitreous (Glassy)
 Streak:
bluish white
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