Phyllosilicate Group

Cavansite

The Blue Puffball

Vivid Electric Blue
Deep Blue Spheres

Quick Facts

FormulaCa(VO)Si₄O₁₀·4H₂O
SystemOrthorhombic
LusterVitreous
StreakLight Blue
TransparencyTransparent to Translucent
Sp. Gravity2.33
Mohs Hardness
3.5

Formation & Origin

Cavansite is a calcium vanadium silicate that forms in volcanic basalt cavities alongside zeolite minerals - the same environment that produces apophyllite and stilbite. The vivid blue color comes from vanadium (V⁴⁺) in the crystal structure.

Cavansite typically grows as spherical aggregates of radiating prismatic crystals - bright blue puffball-like clusters sitting on white zeolite matrix. The visual contrast between electric blue spheres and white stilbite is one of the most striking in mineralogy. The name is an acronym: Ca-Van-Si-Te, from its chemical components (calcium, vanadium, silicon, and the ending from oxygen/ite).

First described in 1967 from Oregon, cavansite remained a rare collector curiosity until the Indian deposits near Pune began producing abundant specimens in the 1990s. The Indian material transformed cavansite from an almost unobtainable rarity to an accessible (though still uncommon) collector mineral.

Identification Guide

Cavansite is identified by its distinctive electric blue color, spherical aggregate crystal habit, and association with zeolite minerals in basalt cavities. The blue spheres on white matrix are unmistakable.

Distinguish from pentagonite (same chemistry, different crystal structure - bladed rather than spherical), azurite (copper carbonate, different blue, different associations), and blue apophyllite (different crystal form, lighter blue). Cavansite's vivid blue spherical clusters are essentially unique among common collector minerals.

Spotting Fakes

Cavansite's distinctive growth habit (spherical blue aggregates on white zeolite matrix) is very difficult to fake convincingly. The main concern is cavansite being confused with pentagonite (a polymorph with the same chemistry but different crystal form). Some low-quality specimens have cavansite spheres enhanced with dye for deeper blue. Natural cavansite varies from pale to deep blue. Artificially deepened color can sometimes be detected under magnification or with acetone testing.

Cultural & Metaphysical Traditions

Presented as cultural traditions, not scientific evidence

Cavansite is too rare and recently described (1967) to have traditional associations. In modern crystal healing, its vivid blue connects it to the throat and third eye chakras. Practitioners associate it with channeling, psychic development, and clear communication of spiritual insights. Its spherical form is interpreted as representing wholeness and completion. The Indian volcanic origin connects it to transformation energy.

Where It's Found

India - Wagholi and Pune, Maharashtra

World's primary source, fine spherical aggregates

United States - Oregon

Original discovery locality (1967), rare

Brazil - Various

Minor occurrences

Price Guide

Entry$15-50 small spheres on matrix
Mid-Range$50-200 quality specimens
Collector$200-2,000+ large or exceptional blue clusters

Good to Know

💎

Scratch test: At hardness 3.5, Cavansite can be scratched with a copper coin. Handle gently and keep away from harder stones in your collection.

🌍

Sources: Found in 3 notable locations worldwide, from India to Brazil.

⚖️

Heft test: With a specific gravity of 2.33, Cavansite feels lighter than most minerals. This lightness can help identify it.