Canvansite
cavansite is a rare mineral from the mineral class the " silicates and Germanate “ . It crystallizes in orthorhombic crystal system with the chemical composition Ca[V 4+ O|Si 4 O 10 ] · 4H 2 O, is therefore a Calcium vanadium layered silicate .
Cavansite is transparent and develops long, prismatic to needle-like Crystals , but also radially rayed mineral aggregates from blue to greenish blue color with glass luster on the surfaces .
Cavansite also belongs to the class of “ silicates and germanates ” and there to the division of “ sheet silicates (phyllosilicates) ” .
The compound Ca[V 4+ O|Si 4 O 10 ] · 4H 2 O is dimorphic and occurs in nature in addition to the orthorhombic crystallizing cavansite and as pentagonite , which is also orthorhombic but crystallizes in a different space group .
Cavansite is formed mainly hydrothermal in cavities of volcanic rocks How basalt and Tuff . As a rare mineral formation, cavansite has only been found in a few locations, although 13 locations are known to date (as of 2012).