Druzy Quartz
Quartz (Silicon Dioxide) var. Druzy · Mineral Specimen / Decorative Stone
Crystal System
Trigonal (Hexagonal); typically shows a massive, druzy, or macro-crystalline habit under magnification.
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2
Formation Process
Hydrothermal; formed by the precipitation of silica-rich fluids in rock cavities or over other minerals at relatively low temperatures.
About This Crystal
The specimen features a cluster of tiny, sparkling white to translucent crystals forming a 'druzy' coating over a dark, fine-grained host rock (possibly basalt or a ferruginous matrix). It exhibits a vitreous luster and characteristic granular texture.
Physical Characteristics
Color: White to colorless crystals on dark matrix; Streak: White; Cleavage: None (poor); Fracture: Conchoidal; Specific Gravity: 2.65; Fluorescence: Usually inert.
Optical Properties
Uniaxial positive; Refractive Index: 1.544-1.553; Birefringence: 0.009. The primary optical appeal is the surface glitter (scintillation) caused by the multiple crystal faces.
Hardness & Durability
Origin Region
Ubiquitous globally; notably Brazil, USA (Arizona), and Uruguay. Found in volcanic vugs, geodes, and hydrothermal vein cavities.
Hardness & Durability
Mohs Hardness: 7; Toughness: Good (crystalline form is durable, though druzy layers can flake if struck); Stability: Highly stable against heat and chemicals.
Care & Maintenance
Wash with warm soapy water and a soft brush; avoid ultrasonic cleaners if the matrix is porous. Store separately to avoid scratching softer stones.
Rarity & Value
Common; Value is determined by the coverage of the druzy, the contrast with the matrix, and the overall aesthetic of the 'sparkle'. Generally affordable for collectors.
Special Characteristics
Scintillation (tiny reflections from multifaceted surfaces); occasionally displays 'phantom' growth if layers of different minerals are present.
Lore & History
Historically used in jewelry and ornamentation since antiquity. In metaphysical lore, quartz is considered a 'master healer' and druzy clusters are believed to amplify the energy of other stones and promote group harmony.