mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Mohs hardness of 7, transparent to translucent clarity, vitreous (glass-like) luster, hexagonal crystal system, conchoidal fracture, specific gravity around 2.65.
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Physical properties
Mohs hardness of 7, transparent to translucent clarity, vitreous (glass-like) luster, hexagonal crystal system, conchoidal fracture, specific gravity around 2.65.
Formation & geological history
Forms through magmatic crystallization in pegmatites, hydrothermal veins, and metamorphic rocks across various geological eras.
Uses & applications
Widely used in gemstone jewelry, ornamental carvings, electronics (piezoelectric applications in quartz watches and radio transmitters), glassmaking, and mineral collections.
Geological facts
Ancient Greeks believed clear quartz was ice frozen so hard that it could never thaw, naming it 'krystallos' from which the word crystal originates. It possesses piezoelectric properties, generating an electric charge under mechanical stress.
Field identification & locations
Identified by its transparency, 7 Mohs hardness (can scratch glass easily and cannot be scratched by a steel nail), conchoidal fracture, and hexagonal prismatic crystal form. Found worldwide in places like Brazil, Arkansas (USA), Madagascar, and the Alps.
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