Mineralpedia Details for Cavansite

Named for the calcium (ca), vanadium (van), and silicon (si) in the composition of the mineral. Cavansite is a rare mineral that occurs in the USA in Oregon at the type locality at Owyhee Dam in Malheur County and at the Charles W. Chapman quarry in Columbia County, in several localities in India with noteably remarkable specimens from the Wagholi area in Maharashtra, and newer localities in New Zealand at the Aranga quary on the North Island and in Brazil at the Municipal quarry in Rio Grande do Sul. Cavansite occurs in tuff filling fault fissures, in a basalt and tuff breccias as cavity fillings and in veinlets, and in pores of altered basalt breccias and tuffaceous andesites.

Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/cavansite.pdf

Formula

Ca(V⁴⁺O)Si₄O₁₀·4H₂O 

Crystal System

Orthorhombic 

Cleavage

Good, None, None 

Luster

Vitreous (Glassy) 

Color

greenish blue, dark blue 

Streak

bluish white 

Class

Orthorhombic - Dipyramidal 

Fracture

Brittle 

Hardness

3-4 

WebMineral

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Mindat

View Cavansite 

Deep, lustrous blue crystal sprays to 1cm across perched nicely on white Stilbite and Apophyllite matrix.

Neon blue spray of bladed Cavansite to 8mm on a white Stilbite crystal to 1.3cm.

Deep blue crystal clusters to 1.2cm on Stilbite matrix.

Special Info

Type Locality

Type locality bright blue, platy cavansite. I