Clear Quartz (Rock Crystal)
Quartz (Variety: Rock Crystal) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal; hexagonal-rhombohedral system. Typically occurs as hexagonal prisms terminated by rhombohedra.
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2
Formation Process
Hydrothermal or Igneous; forms in hydrothermal veins, pegmatites, and geodes via precipitation from silica-rich fluids.
About This Crystal
Transparent to translucent colorless specimen with a vitreous luster. This cluster features several intergrown prismatic crystals with visible flat terminations.
Physical Characteristics
Color: Colorless/White; Streak: White; Cleavage: Indistinct; Fracture: Conchoidal; Specific Gravity: 2.65; Fluorescence: Generally inert.
Optical Properties
Refractive Index: 1.544-1.553; Birefringence: 0.009; Doubly refractive (uniaxial positive); Dispersion: 0.013.
Hardness & Durability
Origin Region
Globally distributed; notable sources include Brazil, Arkansas (USA), Madagascar, and the Alps.
Hardness & Durability
Mohs Hardness: 7; Toughness: Good; Highly stable and resistant to most acids except hydrofluoric acid.
Care & Maintenance
Wash with warm soapy water and a soft brush. Avoid extreme thermal shock. Safe for ultrasonic cleaning if no fractures are present.
Rarity & Value
Common; Value is determined by clarity, size, and crystal perfection. Generally low to moderate price range.
Special Characteristics
Piezoelectric and pyroelectric properties. This specific cluster shows a 'growth' habit where multiple points emerge from a central mass.
Lore & History
Historically used for lens making and crystal balls ('scrying'). Traditionally associated with the Crown Chakra and believed to be a 'master healer' in lore.