Druzy Quartz
Quartz (Variety of Alpha-Quartz) · Mineral Specimen / Decorative Stone
Crystal System
Trigonal: Typically found in granular, massive, or as tiny pyramidal druzy coatings on a host matrix.
Mineral Group
Silicates (Tectosilicate subgroup)
Chemical Formula
SiO2
Formation Process
Hydrothermal: Specifically via precipitation of silica-rich fluids into cavities of host rock at low temperatures.
About This Crystal
The specimen features clusters of tiny, transparent to translucent white crystals with a vitreous to sugary luster, sitting atop a dark, opaque, earthy matrix. The crystals exhibit a 'druzy' sparkling effect due to numerous small reflective facets.
Physical Characteristics
Color: White/Clear; Streak: White; Fracture: Conchoidal (for individual crystals); Density: 2.65 g/cm³; Fluorescence: Generally inert, but may show weak green or yellow under UV depending on impurities.
Optical Properties
Refractive Index: 1.544–1.553; Birefringence: 0.009; Optically Uniaxial (+); Non-pleochroic; exhibit sparkling 'scintillation' under direct light.
Hardness & Durability
Origin Region
Globally distributed; notable sources include Brazil, USA, and Morocco. Found in volcanic vugs or sedimentary geodes.
Hardness & Durability
Mohs Hardness: 7. Durability is high for the crystals themselves, but the druzy layer can be brittle and prone to shedding if the matrix is soft.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid ultrasonic cleaners as they may vibrate crystals loose from the matrix. Store away from harder stones like topaz or sapphire.
Rarity & Value
Common; Value is generally low to moderate based on the size of the cluster, sparkle quality, and completeness of the specimen.
Special Characteristics
Displays 'Druzy' effect (a coating of fine crystals); no distinct optical phenomena like asterism are visible in this specific specimen.
Lore & History
Quartz has been used since antiquity for tools and talismans. In lore, druzy quartz is associated with 'harmonizing' groups and enhancing the body's natural healing properties.