Cavansite

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.

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.