Cavansite

Formula: Ca(V4+O)(Si4O10).4H2O phyllosilicate (sheet silicate)
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
Sedimentary environments

Cavansite occurs in zeolites in basalt, and also in Tuff. At Lake Owyhee State Park cavansite occurs in fractures in tuff, associated with zeolites and calcite. Near Pua, India, it occurs in silica-rich breccia.