Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal System; typically occurs in hexagonal prisms terminated by rhombohedral faces, but this specimen is a tumbled/polished pebble habit.
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2
Formation Process
Primarily Magmatic or Hydrothermal; crystallizes from silica-rich fluids and solutions at various temperatures and pressures.
About This Crystal
Clear, colorless transparent stone with a vitreous (glassy) luster. This specimen is a small tumbled stone showing internal fractures and faint cloudy inclusions.
Physical Characteristics
Color: Colorless. Streak: White. Cleavage: None. Fracture: Conchoidal. Specific Gravity: 2.65. Tenacity: Brittle. Generally non-fluorescent.
Optical Properties
Refractive Index: 1.544-1.553. Birefringence: 0.009. Uniaxial positive. It exhibits high transparency and lacks pleochroism.
Hardness & Durability
Origin Region
Found globally, notably Brazil, Madagascar, and the United States (Arkansas); forms in pegmatites and hydrothermal veins.
Hardness & Durability
Mohs Hardness: 7. Excellent durability for jewelry; lacks cleavage making it resistant to chipping compared to other gems.
Care & Maintenance
Safe for ultrasonic and steam cleaning. Use warm soapy water. Highly stable, though avoid extreme thermal shock; does not fade in sunlight.
Rarity & Value
Common; value depends on clarity and size. Transparent, inclusion-free pieces are preferred but abundant. Treatments like irradiation or coating are common for other varieties, but clear quartz is usually natural.
Special Characteristics
Piezoelectric and pyroelectric properties. This specific piece shows internal veiling and 'rainbow' reflections from internal fractures.
Lore & History
Historically called 'Ice of the Gods.' Used in ancient Greece and Rome. Traditionally associated with the Crown Chakra and believed to be a 'master healer' and amplifier of energy.