Formula: Ca(V4+O)(Si4O10).4H2O
Phyllosilicate (sheet silicate), paramorph of
pentagonite, vanadium-bearing
mineral
Specific gravity: 2.21 to 2.31
Hardness: 3 to 4
Streak: Bluish white
Colour: Blue to greenish blue
Solubility: Slightly soluble in acids
Environments:
Volcanic igneous environments
Basaltic cavities
Cavansite occurs as a secondary mineral in
basalt and in
andesite, associated with zeolites, and also
in tuff
(Dana, Webmin).
Localities
At the Wagholi quarry, Pune district, Maharashtra, India, in a few places the dense basalt
has been interuptuded by small breccia zones. In these the rock has been washed out by
hydrothermal solutions, favouring the deposition of stilbite,
heulandite and cavansite, and less frequently,
mordenite and calcite. The Deccan
basalts have an average vanadium content of 300 ppm, but in the Pune area the concentration
is much higher at 600 to 750 ppm. Other than cavansite and pentagonite, no minerals with
essential vanadium have been found in these basalts. Cavansite is generally found to grow
on small heulandite or stilbite crystals,
occasionally with calcite. Very rarely cavansite is found embedded in
mordenite
(Minrec 34.1.41-43).
Here cavansite occurs in pores of the altered basalt
breccia and tuffaceous
andesite associated with stilbite,
calcite, heulandite,
mordenite and chalcocite
(HOM).
At a building construction site near the Wagholi Quarries, Wagholi, Pune District, Pune Division,
Maharashtra, India, in August 2023 specimens were found with spherical cavansite clusters to 2 cm in
diameter spotted at intervals over drusy quartz, with tiny white
stilbite crystals
(Minrec 55.1.90).
At the type locality, the Owyhee Dam, Lake Owyhee State Park, Malheur county, Oregon, USA, cavansite is found in cavities and veinlets
in basalt and in tuff partly ̄filling fractures,
associated with pentagonite, calcite,
heulandite, stilbite,
analcime, apophyllite,
thomsonite and copper
(HOM, Dana, AM 58.405-411).
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