Cavansite is one of the most visually arresting minerals available to collectors today. Its electric blue color, radiating ball-like crystal clusters, and almost impossibly vivid hue make it an instant centerpiece in any display. But not all cavansite is equal — and knowing how to identify high-quality, genuine material is essential for any serious collector.
What Is Cavansite?
Cavansite is a calcium vanadium phyllosilicate hydroxide, first described in 1967 from a deposit in Oregon. Today, the overwhelming majority of collector-grade material comes from the Wagholi quarry near Pune, Maharashtra, India — a zeolite-rich basalt formation that has produced some of the finest specimens ever seen.
The name derives from its chemical composition: Calcium, Vanadium, and Silicate. It is closely associated with stilbite, heulandite, and apophyllite — fellow zeolite-group minerals that commonly appear on the same matrix.
Key Identification Markers
1. Color
Authentic cavansite is a rich, saturated blue — often described as peacock blue or cobalt blue. The color comes from vanadium in the +4 oxidation state. Be cautious of specimens with a washed-out, pale, or greenish tint, which may indicate lower vanadium content, surface alteration, or misidentification as the related mineral pentagonite.
Tip: The finest material displays consistent, deep color throughout the spherical ball clusters — not just at the tips.
2. Crystal Habit
Cavansite forms distinctive rosette or pompon-shaped aggregates of tabular, bladed crystals radiating from a central point. Individual crystals are typically 1–5mm in length. Well-formed balls should be tightly packed, symmetrical, and show clear crystal terminations without excessive breakage or abrasion.
Pentagonite — a polymorph of cavansite with identical chemistry — forms elongated, prismatic crystals rather than ball clusters and is relatively rare. Both are genuine minerals, but pentagonite commands a premium for its unusual habit.
3. Matrix Quality
Provenance-authentic cavansite almost always occurs on a cream to white zeolite matrix — typically stilbite, apophyllite, or heulandite from the Deccan Traps basalt. Examine the matrix for:
- Natural attachment: Clusters should grow directly from the matrix, not appear glued or re-mounted
- Matrix condition: Look for clean, undamaged matrix with minimal repair or reconstruction
- Companion minerals: The presence of well-formed stilbite fans or apophyllite pyramids alongside cavansite is a positive provenance indicator
4. Luster and Surface
Cavansite has a vitreous to pearly luster. Under good light, the crystal faces should show a bright, glassy reflection. Dull or waxy surfaces may indicate surface alteration or that the specimen has been cleaned aggressively.
5. Specific Gravity and Hardness
For those with access to testing equipment: cavansite has a hardness of approximately 3–4 on the Mohs scale and a specific gravity of roughly 2.21–2.31 g/cm³ — relatively light for its size, consistent with its phyllosilicate structure.
Wagholi vs. Oregon Material
Oregon material (the type locality) is scientifically significant but rarely reaches the aesthetic quality of Indian specimens. Wagholi material is what dominates the collector market and what most collectors mean when they refer to cavansite. Legitimate dealers will disclose provenance — always ask.
Red Flags to Watch For
- Unusually bright or uniform color that seems "too perfect" — some material is dyed
- Matrix that looks artificially clean or freshly broken, suggesting re-mounting
- No provenance information offered by the seller
- Pricing far below market for the stated size and quality
Shop Genuine Cavansite Specimens
At Nick's Minerals, every cavansite specimen is sourced directly and described accurately. Browse our current inventory:
- Cavansite Specimen – 139g — a substantial, display-ready piece with deep blue clusters on white stilbite matrix
- Cavansite Specimen – 485g — one of our largest cavansite offerings, exceptional for cabinet display
- Blue Cavansite Specimen – 24g — a compact, well-formed miniature ideal for thumbnail collectors
- Cavansite with Stilbite – 230g — a superb combination piece showcasing cavansite alongside sculptural stilbite fans
Cavansite is a mineral that rewards careful examination. The more you handle quality material, the easier it becomes to recognize — and the harder it becomes to settle for anything less.