Clear Quartz (Rock Crystal)
Quartz var. Rock Crystal · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal; typically exhibits a massive or prismatic habit with conchoidal fractures when broken.
Mineral Group
Silicates (Tectosilicate subgroup)
Chemical Formula
SiO2 (Silicon Dioxide)
Formation Process
Primary formation occurs in hydrothermal veins and pegmatites through the cooling of silica-rich solutions in crustal cavities.
About This Crystal
This specimen is a colorless, transparent to translucent fragment of clear quartz. It displays a strong vitreous luster and lack of visible crystal faces, appearing as a broken chunk with sharp edges.
Physical Characteristics
Color: colorless; Streak: white; Cleavage: none; Fracture: conchoidal (shell-like curves); Specific Gravity: 2.65; Fluorescence: typically inert/none.
Optical Properties
Refracted Index: 1.544-1.553; Birefringence: 0.009 (uniaxial positive); Dispersion: 0.013; no pleochroism.
Hardness & Durability
Origin Region
Found worldwide; major high-quality deposits in Minas Gerais, Brazil; Arkansas, USA; and Madagascar.
Hardness & Durability
Mohs Hardness: 7; Toughness: good; highly durable and stable for daily jewelry wear, resistant to most household chemicals.
Care & Maintenance
Clean with warm soapy water and a soft brush; safe for ultrasonic cleaners. Avoid contact with hydrofluoric acid.
Rarity & Value
Very Common; value is determined by clarity and size. Massive chunks are inexpensive, while perfectly clear large crystals are more valuable.
Special Characteristics
Exhibits strong piezoelectric and pyroelectric properties; this particular specimen shows prominent conchoidal fracture patterns and internal 'veils' or fractures.
Lore & History
Historically used for hardstone carving and lenses since antiquity. In metaphysical traditions, it is known as the 'Master Healer' and is associated with the Crown Chakra.