Clear Quartz (Rock Crystal)
Quartz var. Rock Crystal · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal crystal system, Hexagonal scalenohedral class; habit commonly prismatic with pyramidal terminations
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
SiO2 (Silicon Dioxide) with possible trace inclusions of various elements
Formation Process
Primarily hydrothermal in veins; also igneous (pegmatites) and metamorphic; occurs across wide temperature and pressure ranges
About This Crystal
Transparent to translucent colorless crystal; vitreous luster; exhibits conchoidal fracture patterns as seen in the jagged, glass-like breaks of the image
Physical Characteristics
Colorless body; white streak; no cleavage; conchoidal fracture; specific gravity of 2.65; brittle tenacity; displays piezoelectricity
Optical Properties
Uniaxial positive; refractive index of 1.544–1.553; birefringence of 0.009; no pleochroism; low dispersion
Hardness & Durability
Origin Region
Brazil, Madagascar, Arkansas (USA), and the Alps (Switzerland/Italy) among many global locations
Hardness & Durability
Mohs hardness of 7; high toughness; excellent stability against light and heat; very durable for all jewelry types
Care & Maintenance
Wash with warm soapy water; safe for ultrasonic and steam cleaning unless fractious or containing fluid inclusions (enhydros)
Rarity & Value
Very common mineral; value is generally low but increases based on clarity, size, and unique features like rutilation or phantoms
Special Characteristics
Piezoelectric and pyroelectric properties; can contain various inclusions such as tourmaline needles, chlorite, or aqueous bubbles
Lore & History
Known historically as 'frozen ice' by ancient Greeks; used in various cultures for talismans and tools; traditionally associated with the Crown Chakra and thought to amplify energy in metaphysical circles