Okenita
Okenita is a mineral with formula Ca₃Si₆O₁₅·6H₂O, in the Silicatos (Filosilicatos) group. This specimen comes from Malad Quarry, Mumbai Suburban District, Konkan, Maharashtra, India and joined the Terrium collection in 2024.
Description
Large basaltic geode with several white, silky, perfectly preserved okenite spheres, accompanied by white microcrystals lining the internal walls. Associated with gyrolite, small prismatic apophyllite crystals and crystalline calcite, forming a balanced interior.
About Okenita
Typical Pune district association of okenite and gyrolite developed in amygdaloidal cavities of Deccan basalt. In this specimen, the total absence of yellowish stilbite (often present in pieces of this type) indicates a purer phase formed in a deeper internal pocket, where hydrothermal circulation was more stable and less contaminated by iron oxides. That lack of colour makes it a less common variant of the Pune archetype, more refined and of greater collector interest.
About the locality
Malad Quarry, a classic and world-reference locality for okenite, is now closed and regarded as extinct due to urban pressure that has made extraction unviable. The area now has car parks and buildings of all kinds. Although specimens still reach the market thanks to the large quantity of material extracted between 1970 and 1990, pieces with large cavities and intact fibres are increasingly difficult to find.
Technical data
- Catalogue No.
- 0127
- Composition
- Ca₃Si₆O₁₅·6H₂O
- Name
- Okenita
- Group
- Silicatos (Filosilicatos)
- Category
- Cavella
- Matrix
- Basalto
- Associations
- girolita apofilita calcita
- Mine
- Malad Quarry
- District / Municipality
- Mumbai Suburban District
- Province
- Konkan
- Region
- Maharashtra
- Country
- India
- Size (cm)
- 11 x 8 x 7
- Weight
- 745.7 g
- Acquired
- 2024
- Etymology
- From the Greek "ōkénē" ("hair"), in allusion to its delicate silky fibres.
- Quality
- Muy buena
- Value trend
- Al alza