Colorless through various colors (pink, orange, purple, dark brown) to black
Crystal habit
6-sided prism ending in 6-sided pyramid (typical), drusy, fine-grained to microcrystalline, massive
Twinning
Common Dauphine law, Brazil law, and Japan law
Cleavage
{0110} Indistinct
Fracture
Conchoidal
Tenacity
Brittle
Mohs scale hardness
7 – lower in impure varieties (defining mineral)
Luster
Vitreous – waxy to dull when massive
Streak
White
Diaphaneity
Transparent to nearly opaque
Specific gravity
2.65; variable 2.59–2.63 in impure varieties
Optical properties
Uniaxial (+)
Refractive index
nω = 1.543–1.545 nε = 1.552–1.554
Birefringence
+0.009 (B-G interval)
Pleochroism
None
Melting point
1670 °C (β tridymite); 1713 °C (β cristobalite)[3]
Solubility
Insoluble at STP; 1 ppmmass at 400 °C and 500 lb/in2 to 2600 ppmmass at 500 °C and 1500 lb/in2[3]
Other characteristics
Lattice: hexagonal, piezoelectric, may be triboluminescent, chiral (hence optically active if not racemic)
References
[6][7][8][9]
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is, therefore, classified structurally as a framework silicate mineral and compositionally as an oxide mineral. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar.[10]
Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation from α-quartz to β-quartz takes place abruptly at 573 °C (846 K; 1,063 °F). Since the transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold.
There are many different varieties of quartz, several of which are classified as gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Europe and Asia.
Quartz is the mineral defining the value of 7 on the Mohs scale of hardness, a qualitative scratch method for determining the hardness of a material to abrasion.
^"Quartz". A Dictionary of Geology and Earth Sciences. Oxford University Press. 19 September 2013. ISBN 978-0-19-965306-5.
^ abcDeer, W. A.; Howie, R.A.; Zussman, J. (1966). An introduction to the rock-forming minerals. New York: Wiley. pp. 340–355. ISBN 0-582-44210-9.
^Antao, S. M.; Hassan, I.; Wang, J.; Lee, P. L.; Toby, B. H. (1 December 2008). "State-Of-The-Art High-Resolution Powder X-Ray Diffraction (HRPXRD) Illustrated with Rietveld Structure Refinement of Quartz, Sodalite, Tremolite, and Meionite". The Canadian Mineralogist. 46 (6): 1501–1509. doi:10.3749/canmin.46.5.1501.
^Kihara, K. (1990). "An X-ray study of the temperature dependence of the quartz structure". European Journal of Mineralogy. 2 (1): 63–77. Bibcode:1990EJMin...2...63K. doi:10.1127/ejm/2/1/0063. hdl:2027.42/146327.
^Quartz Archived 14 December 2005 at the Wayback Machine. Mindat.org. Retrieved 2013-03-07.
^Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C., eds. (29 January 1990). "Quartz" (PDF). Handbook of Mineralogy. Vol. III (Halides, Hydroxides, Oxides). Chantilly, VA: Mineralogical Society of America. ISBN 0962209724. Archived (PDF) from the original on 1 April 2010. Retrieved 21 October 2009.
^Quartz Archived 12 November 2006 at the Wayback Machine. Webmineral.com. Retrieved 2013-03-07.
^Hurlbut, Cornelius S.; Klein, Cornelis (1985). Manual of Mineralogy (20 ed.). Wiley. ISBN 0-471-80580-7.
^Anderson, Robert S.; Anderson, Suzanne P. (2010). Geomorphology: The Mechanics and Chemistry of Landscapes. Cambridge University Press. p. 187. ISBN 978-1-139-78870-0.
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon–oxygen tetrahedra...
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comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar, because they are the most resistant minerals to the weathering...
Fused quartz, fused silica or quartz glass is a glass consisting of almost pure silica (silicon dioxide, SiO2) in amorphous (non-crystalline) form. This...
Rutilated quartz is a variety of quartz which contains acicular (needle-like) inclusions of rutile. It is used for gemstones. These inclusions mostly...
element. The oscillator frequency is often used to keep track of time, as in quartz wristwatches, to provide a stable clock signal for digital integrated circuits...
Quartz monzonite is an intrusive, felsic, igneous rock that has an approximately equal proportion of orthoclase and plagioclase feldspars. It is typically...
The room-temperature form of quartz, α-quartz, undergoes a reversible change in crystal structure at 573 °C to form β-quartz. This phenomenon is called...
Quartz Compositor is the display server (and at the same time the compositing window manager) in macOS. It is responsible for presenting and maintaining...
Phantom quartz is a variety of quartz consisting of visible layers of overlapping crystal growths. The outline of the inner crystals can be seen due to...
Quartz fiber is a fiber created from high-purity quartz crystals. It is made by first softening quartz rods (in an oxyhydrogen flame) and then creating...
A quartz arenite or quartzarenite is a sandstone composed of greater than 90% detrital quartz. Quartz arenites are the most mature sedimentary rocks possible...
Amethyst is a violet variety of quartz. The name comes from the Koine Greek αμέθυστος amethystos from α- a-, "not" and μεθύσκω (Ancient Greek) methysko...
Seiko SKA531P1 Kinetic, using a 5M62 caliber Kinetic movement Automatic quartz is a collective term describing watch movements that combine a self-winding...
USS Quartz (IX-150), a Trefoil-class concrete barge designated an unclassified miscellaneous vessel, was the only ship of the United States Navy to be...
Quartz diorite is an igneous, plutonic (intrusive) rock, of felsic composition, with phaneritic texture. Feldspar is present as plagioclase (typically...
electronic quartz watch was invented, which was powered by a battery and kept time with a vibrating quartz crystal. By the 1980s the quartz watch had taken...
of silicon with the chemical formula SiO2, commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica...
Quartz News is an American news program from Quartz hosted by Preeti Varathan that premiered on July 19, 2018 on Facebook Watch. The show is broadcast...
made of a clear, transparent material such as plastic, glass, or fused quartz. Cuvettes are designed to hold samples for spectroscopic measurement, where...
a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content...
City of Quartz: Excavating the Future in Los Angeles is a 1990 book by Mike Davis examining how contemporary Los Angeles has been shaped by different powerful...
heaters. Industrial infrared heaters sometimes use a gold coating on the quartz tube that reflects the infrared radiation and directs it towards the product...
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