Druzy Quartz
Quartz (IMA-approved), variety: Druzy Quartz · Mineral Specimen / Semi-Precious Gemstone
Crystal System
Trigonal crystal system; typical habit is druzy (a coating of tiny, shimmering crystals) on a host matrix, often forming in geodes or fractures.
Mineral Group
Silicates; Tectosilicate subgroup (Framework Silicate)
Chemical Formula
SiO2 (Silicon Dioxide)
Formation Process
Hydrothermal; forms from silica-rich water precipitating in rock cavities, cooled at low temperatures to create a carpet of tiny points.
About This Crystal
A dense coating of tiny, translucent to transparent crystals that create a sparkling effect resembling sugar. This specimen appears as a white-to-clear druzy layer over a dark, matte matrix rock with a vitreous to adamantine luster in the crystalline areas.
Physical Characteristics
Color is colorless / white; streak is white; no cleavage; conchoidal fracture for individual crystals; specific gravity of 2.65; piezoelectric; typically no fluorescence unless trace minerals are present.
Optical Properties
Refractive index of 1.544-1.553; uniaxial positive; weak birefringence of 0.009; shows high dispersion (sparkle) due to the numerous tiny crystal facets.
Hardness & Durability
Origin Region
Brazil, Uruguay, India, and the United States (geodes in volcanic basalts or sedimentary limestone cavities).
Hardness & Durability
Mohs hardness of 7; tough, but the druzy points are susceptible to chipping or being knocked off if abraded against harder surfaces.
Care & Maintenance
Wash with warm, soapy water and a soft brush; avoid ultrasonic cleaners which may loosen the druzy from the matrix; store away from dust to maintain sparkle.
Rarity & Value
Common mineral; value is determined by the uniformity of the coverage, 'sparkle' factor, and size. Typically affordable, ranging from $5 to $50 for small-to-medium specimens.
Special Characteristics
Displays various interference of light (scintillation) across the thousands of micro-facets; some specimens may contain phantom inclusions or mineral staining (e.g., iron giving a gold hue).
Lore & History
Historically used in jewelry and ornamentation since antiquity; in modern crystal healing, it is believed to amplify energy, promote group harmony, and bring light to the spirit.