Mineralpedia Details for Quartz

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Quartz

The name for Quartz is believed to be first applied in the Middle Ages to gangue in Saxony, Germany, however the word itself is of obscure origin. Quartz in the most abundant mineral on the surface of the Earth and can be found in a number of environments including hydrothermal veins and metallic deposits, within granites and granite pegmatite, in sandstones, quartzite, and in carbonate rocks. There are hundreds of varieties of quartz which include chalcedonies, agates, and jaspers among others that differ in color, habits, inclusions, and impurities. There are tens of thousands of localities for quartz. Quartz is piezoelectric, develops a charge in response to pressure, and pyroelectric, develops a charge in response to heat and can also be triboluminescent, meaning it can generate light when broken.

Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/quartz.pdf

Formula: SiO₂
Crystal System: Trigonal
Crystal Habit: Crystalline - Coarse, Druse, Crystalline - Fine
Cleavage: Indistinct, None, None
Luster: Vitreous (Glassy)
Color: brown, colorless, violet, gray, yellow
Streak: white
Class: Trigonal - Trapezohedral
Fracture: Conchoidal
Hardness: 7
WebMineral: View Quartz
Mindat: View Quartz

Quartz var. Opal from Yowah, Queensland, Australia

Flashing purple and blue internal reflections of Opal.

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Quartz from Serra Negra, Patrocinio, Minas Gerais, Brazil

Group of opaque white sceptored Quartz crystals to 4cm long.

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Quartz from Lavra Da Ilha, Taquaral, Itinga, Minas Gerais, Brazil

Large pink or rose Quartz in a good crystal group with the largest at 1cm. This is a good clean specimen of rose Quartz from probably one of the best locailties in the worls.