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Chemical name Silicon dioxide
Chemical formula SiO2
Colors Clear (with no impurities)
Crystal habit 6-sided prism ending in 6-sided pyramid
Crystal system rhombohedral
Cleavage None
Fracture Conchoidal
Hardness 7
Name origin German "Quarz".
Specific gravity 2.65
Streak White

Quartz is the second most common mineral found on Earth being the primary component of sand. More accurately known as silicon dioxide, quartz has a chemical composition of SiO2 arranged in a repeating lattice forming hexagonal crystals. Pure quartz is clear, but colored variations are created because of impurities in the crystal. Quartz is number 7 on the Mohs Hardness Scale.
Quartz is used in a number of applications; most commonly in glass making but also abrasives, electrical components or decorative gemstones especially if colored by impurities.