Calciovolborthite
1 in the gallery
Calciovolborthite is a rare calcium copper vanadate that occurs as often small, prismatic crystals with a vitreous to resinous luster. The mineral typically forms in secondary hydrothermal environments, with crystallization yielding elongated, sometimes tabular shapes that can cluster into compact aggregates. Color can range from pale to deeper orange-brown, sometimes with a subtle greenish tint, and crystals frequently display a sharp, well-formed termination.
- Formula
- CaCu(VO4)(OH)
- Rarity
- Uncommon
- Stability
- Stable
- Collector interest
- Moderate Interest
- Classification notes
- Vanadate; adelite–descloizite group
Key characteristics
- Crystal system
- orthorhombic
- Mohs hardness
- 3.5–4
- Specific gravity
- 3.7–3.8
- Luster
- vitreous
- Transparency
- transparent, translucent
- Color
- green, yellow, brown
- Streak
- green, yellow
- Cleavage
- none
- Fracture
- uneven, conchoidal
- Crystal habit
- prismatic, tabular, acicular, radiating, granular, massive
About Calciovolborthite
Notable specimens have been reported from several historic locales in Bolivia and China, where hydrothermal activity and vanadate-bearing rocks contribute to its growth. Collectors prize Calciovolborthite for its rarity and the contrast of color against mineral hosts, as well as the diagnostic crystal forms seen in well-prepared pieces. While individual crystals may be small, high-quality samples can exhibit crisp faces and good luster, making them attractive for display and study alike.