Clear Quartz (Rock Crystal)
Quartz var. Rock Crystal (Alpha-Quartz) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal; typically hexongonal prismatic habit with pyramidal terminations, though this specimen is massive/cleaved.
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2 (Silicon Dioxide)
Formation Process
Hydrothermal and Igneous; crystallizes from silica-rich solutions in veins or during the cooling of molten rock.
About This Crystal
A colorless, transparent to translucent specimen with a vitreous (glassy) luster. Shows internal fractures and inclusions common in raw milky to clear transition zones.
Physical Characteristics
Color: Colorless/White; Streak: White; Cleavage: Indistinct; Fracture: Conchoidal to uneven; Specific Gravity: 2.65; Fluorescence: Usually none.
Optical Properties
Refractive Index: 1.544-1.553; Double refraction (uniaxial positive); negligible pleochroism; low dispersion.
Hardness & Durability
Origin Region
Globally distributed; notable sources include Brazil, Arkansas (USA), and Madagascar. Found in pegmatites and hydrothermal veins.
Hardness & Durability
Mohs Hardness: 7; Toughness: Good; very stable for jewelry use and resistant to most household chemicals.
Care & Maintenance
Safe to clean with warm soapy water or ultrasonic cleaners. Generally resistant to sunlight fading, unlike its colored varieties.
Rarity & Value
Very common; value is determined by clarity, size, and presence of interesting inclusions (like rutilation).
Special Characteristics
Piezoelectric and pyroelectric properties; this specimen shows typical conchoidal ribbing on fractured surfaces.
Lore & History
Historically used for seals and carvings in Ancient Greece and Rome. Traditional lore refers to it as the 'Master Healer,' associated with the Crown Chakra.