Clear Quartz
Quartz var. Rock Crystal · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal; typically hexaganol prisms with pyramidal terminations in natural state; this specimen is tumble-polished (massive form habit).
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2 (Silicon Dioxide)
Formation Process
Primarily Magmatic or Hydrothermal; crystallizes from silica-rich solutions in veins, geodes, and igneous rocks over a wide range of temperatures.
About This Crystal
Colorless and transparent specimen with a vitreous (glass-like) luster. It exhibits a smooth, rounded surface due to tumble-polishing and shows internal clarity with minimal visible inclusions.
Physical Characteristics
Color: Colorless; Streak: White; Cleavage: None/Indiscernible; Fracture: Conchoidal; Specific Gravity: 2.65; Fluorescence: Usually inert.
Optical Properties
Refractive Index: 1.544–1.553; Birefringence: 0.009 (uniaxial positive); Dispersion: 0.013; Transparency: Transparent.
Hardness & Durability
Origin Region
Brazil, Madagascar, USA (Arkansas/New York), and the Alps. Found in pegmatites and hydrothermal veins.
Hardness & Durability
Mohs Hardness: 7; Toughness: Good; Highly stable and resistant to most household chemicals; suitable for all jewelry types.
Care & Maintenance
Clean with warm soapy water and a soft brush. Ultrasonic and steam cleaning are generally safe unless internal fractures (veils) are present. Store away from diamonds to avoid scratching.
Rarity & Value
Common; Value is generally low ($1-$10 for small tumbles) and determined by clarity and size. Treatments are rare for clear quartz, though irradiation can turn it smoky.
Special Characteristics
Piezoelectric and pyroelectric properties; this specific polished piece shows bright specular highlights under direct lighting.
Lore & History
Known as the 'Master Healer' in metaphysical traditions. Historically used by Ancient Greeks who believed it was 'krystallos' (permanent ice). Used for optics, carvings, and divination 'crystal balls' for centuries.