
mineral
Clear quartz crystal
Quartz (silicon dioxide, SiO₂)
AI-generated identification · may be incorrectHardness 7 Mohs; colorless to smoky-clear, with a vitreous luster and transparent body. Quartz is trigonal and commonly forms six-sided prisms with pyramidal terminations, though this specimen appears cut or partly polished; cleavage is absent and fracture is conchoidal.
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Physical properties
Hardness 7 Mohs; colorless to smoky-clear, with a vitreous luster and transparent body. Quartz is trigonal and commonly forms six-sided prisms with pyramidal terminations, though this specimen appears cut or partly polished; cleavage is absent and fracture is conchoidal.
Formation & geological history
Forms when silica-rich fluids or melts crystallize in veins, cavities, and igneous rocks, commonly from the Precambrian through modern geological time. Its planar faces and truncated geometry suggest human cutting rather than a natural crystal termination.
Uses & applications
Used in glass, ceramics, electronics, watches, optical instruments, and abrasives; clear crystals are also sold as decorative or metaphysical specimens. This modest cut specimen has primarily ornamental value.
Geological facts
Quartz is piezoelectric, producing an electrical charge under pressure and enabling quartz oscillators in clocks and electronics. Its transparency comes from low absorption and limited internal impurities.
Field identification & locations
Identify by its glassy luster, high hardness, lack of cleavage, and ability to scratch ordinary glass; it is not readily scratched by a steel knife. Common localities include Brazil, Madagascar, Arkansas, and the Alps.
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