Okenite and Prehnite on Quartz
Okenite / Prehnite var. Calcium Silicate Hydrate · Mineral Specimen
Crystal System
Triclinic (Okenite) and Orthorhombic (Prehnite); botryoidal and fibrous crystal habits
Mineral Group
Silicates (specifically Inosilicate and Phyllosilicate/Tectosilicate associations)
Chemical Formula
Ca3Si2O5(OH)4 (Okenite) and Ca2Al(AlSi3O10)(OH)2 (Prehnite)
Formation Process
Hydrothermal and secondary low-temperature mineral precipitation in vesicles and cavities of basaltic volcanic rocks (Deccan Traps)
About This Crystal
The specimen features distinct spherical botryoidal aggregates of pale to olive green prehnite alongside cotton-ball-like fibrous clusters of white okenite, nestled on a white crystalline quartz and chalcedony matrix.
Physical Characteristics
Color ranges from white to pale yellowish-green; white streak; Mohs hardness varies from 4.5 to 5 for okenite and 6 to 6.5 for prehnite; uneven fracture; specific gravity around 2.3 to 2.9 depending on the mineral phase
Optical Properties
Vitreous to pearly luster; translucent to opaque; biaxial positive with low to moderate birefringence
Hardness & Durability
Origin Region
Pune district, Maharashtra, India (Deccan Traps); also found in parts of the USA, Mali, and Australia
Hardness & Durability
Variable hardness (Okenite is very soft at 4.5, Prehnite is moderately hard at 6); poor durability for jewelry due to the delicate fibrous nature of okenite and brittle botryoidal forms; best displayed as a mineral specimen
Care & Maintenance
Extremely fragile; avoid ultrasonic or steam cleaners, harsh chemicals, and water soaking due to the fibrous, delicate structure of okenite; clean gently with a soft dry brush if necessary
Rarity & Value
Uncommon to rare fine combination specimens; high aesthetic value depends on the balance, undamaged spheres, and contrast between okenite cotton-balls and green prehnite on matrix; price ranges from moderate to high for large showy pieces
Special Characteristics
Striking combination of fibrous radiating okenite 'cotton balls' and smooth, rounded botryoidal prehnite globules on a contrasting white quartz matrix
Lore & History
Popular among modern crystal collectors for its unique tactile appearance; in metaphysical lore, okenite is associated with unconditional forgiveness and peace, while prehnite is known as a stone of unconditional love and connecting to higher realms, though these are traditional beliefs without scientific backing