Clear Quartz (Rock Crystal)
Quartz (alpha-quartz) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal; typically occurs as hexagonal prisms terminated by rhombohedra
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2
Formation Process
Hydrothermal (precipitated from silica-rich fluids in veins or geode cavities) or Igneous
About This Crystal
Transparent to translucent colorless specimen with a vitreous (glassy) luster and uneven sugary surface texture
Physical Characteristics
Colorless; white streak; no cleavage; conchoidal to uneven fracture; SG: 2.65; typically non-fluorescent
Optical Properties
Uniaxial positive; RI 1.544-1.553; circular birefringence; non-pleochroic; low dispersion
Hardness & Durability
Origin Region
Found globally; notable sources include Brazil, Arkansas (USA), and Madagascar
Hardness & Durability
Mohs hardness of 7; high toughness; extremely stable and suitable for all jewelry types
Care & Maintenance
Wash with warm soapy water; safe for ultrasonic cleaning; resistant to most household chemicals
Rarity & Value
Very common; value is determined by clarity and size; generally inexpensive for small specimens
Special Characteristics
Piezoelectric and pyroelectric properties; this specimen appears to be a small geode fragment or druzy
Lore & History
Historically used for tools and optical lenses; traditionally known as the 'Master Healer' in cultural lore