Apophyllite (Stilbite-coated)
Fluorapophyllite-(K) with Stilbite-Ca · Collector Mineral Specimen
Crystal System
Tetragonal (Apophyllite) and Monoclinic (Stilbite); typically occurs as sugary druzy or botryoidal crusts.
Mineral Group
Silicates (Phyllosilicates and Zeolites)
Chemical Formula
KCa4Si8O20(F,OH)·8H2O with NaCa4(Si27Al9)O72·28H2O
Formation Process
Hydrothermal mineralization: secondary minerals precipitated from low-temperature hydrothermal fluids in volcanic basalt cavities.
About This Crystal
A cluster of translucent to transparent colorless crystals with a vitreous to pearly luster. Features a fine, 'sugary' druzy texture that causes brilliant sparkling (scintillation) across the surface when lit.
Physical Characteristics
Color: Colorless to white; Streak: White; Cleavage: Perfect on {001}; Fracture: Uneven; Specific Gravity: 2.3–2.4; Luster: Pearly on cleavage faces, vitreous elsewhere.
Optical Properties
Uniaxial (+); Refractive Index: 1.530-1.544; often exhibits internal rainbows due to light interference in cleavage planes or fractures.
Hardness & Durability
Origin Region
Maharashtra, India (Deccan Traps); found in volcanic basalt cavities.
Hardness & Durability
Mohs hardness: 4.5 to 5. Low toughness; brittle and sensitive to heat and pressure. Not suitable for most jewelry applications.
Care & Maintenance
Clean with cool, soapy water and a soft brush; avoid ultrasonic cleaners, steam, and harsh chemicals. Store away from direct sunlight to prevent dehydration.
Rarity & Value
Relatively common but highly valued for aesthetic appeal. Price varies by size, brilliance, and the lack of damage to the delicate crystal tips.
Special Characteristics
Displays 'diamond-like' scintillation in light; some specimens show weak green or yellow fluorescence under shortwave UV light.
Lore & History
Historically used as a high-vibration stone in modern mineral lore; associated with the Crown Chakra and believed to facilitate mental clarity and spiritual connection.