Pentagonita
Pentagonita is a mineral with formula Ca(VO)Si₄O₁₀·4H₂O, in the Silicatos (Filosilicatos) group. This specimen comes from Wagholi Quarry, Wagholi, Pune, Maharashtra, India and joined the Terrium collection in 2025.
Description
Electric-blue acicular pentagonite crystals, grouped in a main spray rising from the base and ending in small rosettes. The aggregate is surrounded and supported by transparent heulandite crystals.
About Pentagonita
Pentagonite is a rare mineral, produced in significant quantity almost exclusively in India. It is distinguished by its electric blue colour and acicular crystals in fan sprays. It shares composition with cavansite but has a different structure and is far less common.
About the locality
The only producing locality. The Wagholi quarries, in Pune (India), form part of the Deccan basalts. In their zeolite-rich cavities, unique specimens have formed.
Technical data
- Catalogue No.
- 0065
- Composition
- Ca(VO)Si₄O₁₀·4H₂O
- Name
- Pentagonita
- Group
- Silicatos (Filosilicatos)
- Category
- Cavella
- Matrix
- Basalto
- Associations
- heulandita
- Mine
- Wagholi Quarry
- District / Municipality
- Wagholi
- Province
- Pune
- Region
- Maharashtra
- Country
- India
- Size (cm)
- 3 x 3 x 2.5
- Weight
- 20 g
- Acquired
- 2025
- Etymology
- The name refers to the pentagonal arrangement of some crystal groups, observed in ideal views. It was described as a species in 1973.
- Quality
- Buena
- Value trend
- Estable