mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Hardness: 7 on Mohs scale; Color: Colorless/transparent; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None; Specific Gravity: 2.65
- Hardness
- 7 on Mohs scale
- Color
- Colorless/transparent
- Luster
- Vitreous (glassy)
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Physical properties
Hardness: 7 on Mohs scale; Color: Colorless/transparent; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None; Specific Gravity: 2.65
Formation & geological history
Forms in igneous rocks like pegmatites, metamorphic rocks, and sedimentary environments via hydrothermal activity. It can precipitate from hot silica-rich solutions in veins.
Uses & applications
Used in glassmaking, electronics (piezoelectric properties), jewelry, gemstones, and as a popular specimen for mineral collectors.
Geological facts
Quartz is one of the most abundant minerals on Earth's crust. 'Rock crystal' comes from the Greek word 'krystallos,' meaning ice, as ancient Greeks believed it was permanently frozen water.
Field identification & locations
Identify by its six-sided prismatic shape, lack of cleavage (it fractures like glass), and its ability to scratch glass. Found worldwide, with major deposits in Brazil and Arkansas, USA.
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