mineral
Quartz (Clear Quartz / Rock Crystal)
Silicon Dioxide (SiO2)
Hardness: 7 on Mohs scale. Color: Colorless and transparent. Luster: Vitreous (glassy). Crystal system: Trigonal/Hexagonal. Cleavage: Poor/None, conchoidal fracture. Specific gravity: 2.65.
- Hardness
- 7 on Mohs scale
- Color
- Colorless and transparent
- Luster
- Vitreous (glassy)
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Physical properties
Hardness: 7 on Mohs scale. Color: Colorless and transparent. Luster: Vitreous (glassy). Crystal system: Trigonal/Hexagonal. Cleavage: Poor/None, conchoidal fracture. Specific gravity: 2.65.
Formation & geological history
Forms in a wide variety of geological environments including igneous, metamorphic, and sedimentary rocks. Typically crystallizes from cooling magma, hydrothermal fluids, or pegmatites.
Uses & applications
Used in jewelry, gemstone carvings, electronics (piezoelectric oscillators), optics, glass manufacturing, and highly popular among mineral collectors.
Geological facts
Quartz is the second most abundant mineral in Earth's continental crust. Ancient Greeks believed clear quartz was ice frozen so hard that it would never melt, calling it 'krystallos'.
Field identification & locations
Identified by its ability to scratch glass (hardness 7), glassy luster, lack of distinct cleavage, and conchoidal fracture. Commonly found worldwide in granites, pegmatites, quartzites, and stream gravels.
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