Quartz

Quartz crystal cluster from Brazil

General
Category| Tectosilicate minerals
Formula
(repeating unit)| SiO2
Strunz classification| 4.DA.05 (oxides)
Dana classification| 75.01.03.01 (tectosilicates)
Crystal system| α-quartz: trigonal
β-quartz: hexagonal
Crystal class| α-quartz: trapezohedral (class 3 2)
β-quartz: trapezohedral (class 6 2 2)[1]
Space group| α-quartz: P3221 (no. 154)[2]
β-quartz: P6222 (no. 180) or P6422 (no. 181)[3]
Unit cell| a = 4.9133 Å, c = 5.4053 Å; Z = 3
Identification
Formula mass| 60.083 g·mol−1
Color| Colorless, pink, orange, white, green, yellow, blue, purple, dark brown, or 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| none[4]
Fracture| Conchoidal
Tenacity| Brittle
Mohs scale hardness| 7 – lower in impure varieties (defining mineral)
|re|er}}| 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)[1]
Solubility| Insoluble at STP; 1 ppmmass at 400 °C and 500 lb/in2 to 2600 ppmmass at 500 °C and 1500 lb/in2[1]
Other characteristics| Lattice: hexagonal, piezoelectric, may be triboluminescent, chiral (hence optically active if not racemic)
References| [5][6][7][8]
Major varieties
Rock crystal| Clear
Milky quartz| White
Amethyst| Violet
Citrine| Yellow
Smoky quartz| Gray to black, brown
Rose quartz| Pink

Quartz is a hard mineral composed of silica (silicon dioxide). Its atoms are linked in a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen atom being shared between two tetrahedra, giving an overall chemical formula of SiO2. Therefore, quartz is classified structurally as a framework silicate mineral and compositionally as an oxide mineral. Quartz is the second most common mineral or mineral group in Earth's lithosphere, comprising about 12% by mass.

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.

## Contents

* 1 Etymology
* 2 Early studies
* 3 Crystal habit and structure
* 4 Varieties
* 5 Piezoelectricity
* 6 Occurrence
* 7 Mining
* 8 Related silica minerals
* 9 Safety
* 10 Synthetic and artificial treatments
* 11 Uses
* 12 See also
* 13 References
* 14 External links

## Etymology

The word quartz is derived from the German word Quarz,[10] which had the same form in the first half of the 14th century in Middle High German and in East Central German[11] and which came from the Polish dialect term kwardy, which corresponds to the Czech term tvrdý ('hard').[12] Some sources, however, attribute the word's origin to the Saxon word Querkluftertz, meaning 'cross-vein ore'.[13][14]

The Ancient Greeks referred to quartz as κρύσταλλος (krustallos) meaning 'crystal', derived from the Ancient Greek κρύος (kruos) meaning 'icy cold', because some philosophers (including Theophrastus) believed the mineral to be a form of supercooled ice.[14] Today, the term rock crystal is sometimes used as an alternative name for transparent, coarsely crystalline quartz.[15][16]: 205

## Early studies

Roman naturalist Pliny the Elder believed quartz to be ice, permanently frozen after great lengths of time.[17] He supported this idea by saying that quartz is found near glaciers in the Alps, but not in warm climates. This idea persisted until at least the 17th century.[18]

In the 17th century, Nicolas Steno's study of quartz paved the way for modern crystallography. He discovered that, regardless of a quartz crystal's size or shape, its long prism faces always meet at a perfect 60° angle, thereby establishing the law of constancy of interfacial angles.[19]

## Crystal habit and structure

Crystal structure of α-quartz (red balls are oxygen, gray are silicon)

Crystal structure of β-quartz

A chiral pair of α-quartz

Quartz can form as two distinct polymorphs depending on the temperature and pressure: α-quartz (also called low quartz or normal quartz) and β-quartz (also called quartz-beta or high quartz). α-quartz crystallizes in the trigonal crystal system, while β-quartz has greater symmetry and crystallizes in the hexagonal crystal system. The transition from α-quartz to β-quartz occurs abruptly at 573 °C (1,063 °F; 846 K) at ambient pressure; the transition temperature is greater at higher pressures. β-quartz is unstable at room temperature; therefore, all quartz at room temperature is α-quartz regardless of which polymorph it formed as.[20]

Both polymorphs of quartz can occur in two different space groups depending on the chirality. Above the transition temperature, α-quartz in P3121 (space group 152) becomes β-quartz in P6422 (space group 181), and α-quartz in P3221 (space group 154) becomes β-quartz in P6222 (space group 180).[21]

These space groups are truly chiral (they each belong to the 11 enantiomorphous pairs). Both α-quartz and β-quartz are examples of chiral crystal structures composed of achiral building blocks (SiO4 tetrahedra in the present case). The transformation between α- and β-quartz only involves a comparatively minor rotation of the tetrahedra with respect to one another, without a change in the way they are linked.[8][16]: 201 However, there is a significant change in volume during this transition,[22] and this can result in significant microfracturing in ceramics during firing,[23] in ornamental stone after a fire[24] and in rocks of the Earth's crust exposed to high temperatures,[25] thereby damaging materials containing quartz and degrading their physical and mechanical properties.

The ideal crystal shape for quartz is a six-sided prism terminating with six-sided pyramid-like rhombohedrons at each end. In nature, quartz crystals are often twinned (with twin right-handed and left-handed quartz crystals), distorted, or so intergrown with adjacent crystals of quartz or other minerals as to only show part of this shape, or to lack obvious crystal faces altogether and appear massive.[8][16]: 202–204

Well-formed crystals typically form as a druse (a layer of crystals lining a void), of which quartz geodes are particularly fine examples.[26] The crystals are attached at one end to the enclosing rock, and only one termination pyramid is present. However, doubly terminated crystals do occur where they develop freely without attachment, for instance, within gypsum.[27]

* Common, prismatic quartz

* Error creating thumbnail:

Sceptered quartz

* Error creating thumbnail:

Sceptered quartz (as aggregates: "Elestial quartz")

* Error creating thumbnail:

Bipyramidal quartz

* Error creating thumbnail:

Tessin or tapered quartz

* Error creating thumbnail:

Twinned quartz (known as Japan law)

* Error creating thumbnail:

Dauphine quartz (single dominant face)

* Error creating thumbnail:

"Herkimer diamond"

* Error creating thumbnail:

Druse quartz

* Granular quartz

* Error creating thumbnail:

Massive quartz

## Varieties

Clear quartz crystal demonstrating transparency

Pure quartz, traditionally called rock crystal or clear quartz, is colorless and transparent or translucent. Colored varieties of quartz are common and include citrine, rose quartz, amethyst, smoky quartz, milky quartz, and others.[28] These color differentiations arise from the presence of impurities which change the molecular orbitals, causing some electronic transitions to take place in the visible spectrum, emitting colored light. Quartz varieties were previously classified into three categories based on the visibility of their individual crystals. Macrocrystalline quartz varieties have individual crystals that are visible to the unaided eye (macroscopic). Microcrystalline quartz varieties are aggregates of tiny crystals that can only be seen through a microscope (microscopic). Cryptocrystalline quartz varieties are aggregates of crystals that are too small to be seen even with an optical microscope (sub-microscopic).[29] Today, the microcrystalline and cryptocrystalline varieties are commonly grouped together and referred to as chalcedony.[29][30] However, in the scientific literature, chalcedony is a specific form of silica consisting of fine intergrowths of both quartz and its monoclinic polymorph, moganite.[31][30] Chalcedony is commonly translucent to opaque, while the macrocrystalline varieties of quartz tend to be more transparent.[32][29] Color is a secondary identifier for the cryptocrystalline varieties and a primary identifier for the macrocrystalline varieties.[32]

Varieties of quartz  Name | Color | Cause | Description | Crystal visibility | Transparency | Major sources | Photo(s) | References

|
|
|
|
|
|
|
|

Agate | Frequently multicolored; commonly colorless, pale blue to black, red to orange, yellow, white, brown, pink, purple; rarely green | Varies by color | Banded variety of chalcedony | Cryptocrystalline, microcrystalline | Translucent to opaque | Widespread | 150px Agate nodule from Malawi | [33][34]
Amethyst | Purple to violet | Natural irradiation and trace impurities of iron (Fe3+) | Commonly occurs in large clusters and geodes | Macrocrystalline | Transparent | Brazil, Mexico, Uruguay, Russia, France, Namibia, Morocco | 150px Amethyst cluster from Siberia | [35][36]
Ametrine | Violet and yellow | Iron impurities | Commonly believed to be a combination of citrine and amethyst in the same crystal, although the yellow quartz component may not be true citrine. Most material sold as ametrine is partially heat-treated or artificially irradiated amethyst. | Macrocrystalline | Transparent to translucent | Bolivia, Brazil, India | 150px Rough ametrine from Bolivia

150px Cut ametrine | [37][38]
Carnelian | Orange to red, red-brown | Iron oxide impurities | Variety of chalcedony. Natural carnelian is usually light in color; darker colors are produced by artificial heat treatment. | Cryptocrystalline, microcrystalline | Translucent to opaque | Peru, Sri Lanka | 150px Natural carnelian from New Jersey, U.S.

150px Carnelian cabochons | [39]
Chalcedony | Almost any color | Varies by color | Fibrous form of silica composed mostly of quartz with some intergrown moganite (1-20%), occurs in many sub-varieties | Cryptocrystalline, microcrystalline | Transparent to opaque | Widespread | 150px Chalcedony from Czech Republic | [30]
Citrine | Natural:
yellow to yellow-green or yellow-orange, often with smoky hues

Heat-treated amethyst:
yellow-orange, orange, red, brown | Natural:
no scientific consensus (either aluminum color centers or trace iron impurities)

Heat-treated amethyst:
trace amounts of iron oxides (hematite and goethite) | Natural citrine is rare; most material sold as citrine is heat-treated amethyst or sometimes heat-treated smoky quartz. Quartz colored yellow from stains, coatings, or inclusions is generally not considered citrine. | Macrocrystalline | Transparent | Brazil | 150px Twinned natural citrine crystals from Russia

150px "Citrine" (heat-treated amethyst) geode | [40][41][42]
Cotterite | Silvery metallic sheen | Develops in very thin layers with extremely thin cracks that produce a light-scattering effect giving cotterite a pearly metallic luster | Extremely rare. Derived from a single vein of calcite, quartz and ferruginous mud in Carboniferous Limestone in Rockforest, County Cork, Ireland | Macrocrystalline | Opaque | Ireland | Cotterite - The World’s Rarest form of Quartz Cotterite from Ireland | [43][44][45]
Dumortierite quartz | Blue, shades of purple and gray | Mineral inclusions | Contains silky inclusions of blue dumortierite | Macrocrystalline | Translucent |  | 150px Dumortierite quartz from Brazil | [46][47][48]
Jasper | Typically red to brown; may have other colors |  | Impure variety of chalcedony | Microcrystalline | Opaque |  | 150px Red jasper from Japan |
Milky quartz | White | Minute fluid inclusions of gas, liquid, or both, trapped during crystal formation | Less desirable as a gemstone | Macrocrystalline | Translucent to opaque |  | 150px Milky quartz from Colorado, USA | [49][50]
Onyx | Black and white, monochromatic | Carbon impurities | Variety of agate | Cryptocrystalline, microcrystalline | Semi-translucent to opaque |  | 150px Onyx from Germany |
Prase | Leek green | Inclusions of the amphibole mineral actinolite | As originally defined in Germany. The name prase has also been used historically for similarly-colored quartzite and jasper, and today it may refer to any leek-green quartz. | Macrocrystalline |  |  | 150px Prase from Tuscany, Italy | [51][52]
Prasiolite (vermarine, green amethyst) | Green | Trace Fe2+ compounds | Rare. Most material sold as prasiolite is produced by heating amethyst. | Macrocrystalline | Transparent | Brazil; Thunder Bay, Canada; Poland | 150px Cut prasiolite from Brazil | [53][54]
Rock crystal (clear quartz) | Colorless | Absence of impurities |  | Macrocrystalline | Transparent to translucent |  | 150px Clear quartz crystals |
Rose quartz | Pale pink to rose | Microscopic inclusions of a fibrous mineral related to dumortierite

Euhedral rose quartz: aluminum and phosphorus color centers | Rose quartz is always massive and anhedral. However, a distinct variety called euhedral rose quartz or pink quartz occurs as well-formed hexagonal crystals. | Macrocrystalline | Translucent

Euhedral rose quartz: transparent |  | 150px Rose quartz

150px Euhedral rose quartz (pink quartz) cluster from Minas Gerais, Brazil | [55][56][57]
Rutilated quartz | Clear with golden-yellow or black inclusions | Mineral inclusions | Contains acicular (needle-like) inclusions of rutile | Macrocrystalline | Transparent to translucent |  | 150px Rutilated quartz cluster from Brazil |
Smoky quartz | Light to dark gray, brown, black | Color centers around aluminum impurities activated by natural irradiation |  | Macrocrystalline | Translucent to opaque |  | 150px Smoky quartz from Brazil | [58]
Tiger's eye | Gold, red-brown, blue |  | Exhibits chatoyancy | Macrocrystalline | Opaque |  | 150px Rough tiger's eye

150px Polished red tiger's eye |

## Piezoelectricity

Quartz crystals have piezoelectric properties; they develop an electric potential upon the application of mechanical stress.[59] Quartz's piezoelectric properties were discovered by Jacques and Pierre Curie in 1880.[60][61]

## Occurrence

File:Quartz vein in sandstone (Thunderhead Sandstone, Neoproterozoic; Clingmans Dome, Great Smoky Mountains, North Carolina, USA) 2 (36619574200).jpgQuartz vein in sandstone, North Carolina

Quartz is the second most abundant mineral or mineral group in the Earth's lithosphere; by mass, the feldspar group comprises 41% of the lithosphere, followed by quartz at 12% and the pyroxene group at 11%.[62] Quartz is a defining constituent of granite and other felsic igneous rocks. It is very common in sedimentary rocks such as sandstone and shale. It is a common constituent of schist, gneiss, quartzite and other metamorphic rocks.[8] Quartz has the lowest potential for weathering in the Goldich dissolution series and consequently it is very common as a residual mineral in stream sediments and residual soils. Generally a high presence of quartz suggests a "mature" rock, since it indicates the rock has been heavily reworked and quartz was the primary mineral that endured heavy weathering.[63]

While the majority of quartz crystallizes from molten magma, quartz also chemically precipitates from hot hydrothermal veins as gangue, sometimes with ore minerals such as gold, silver and copper. Large crystals of quartz are found in magmatic pegmatites.[8] Well-formed crystals may reach several meters in length and weigh hundreds of kilograms.[64]

The largest documented single crystal of quartz was found near Itapore, Goiaz, Brazil; it measured approximately 6.1 m × 1.5 m × 1.5 m (20 ft × 5 ft × 5 ft) and weighed over 39,900 kg (88,000 lb).[65]

## Mining

Quartz is extracted from open-pit mines. Miners occasionally use explosives to expose deep pockets of quartz. More frequently, bulldozers and backhoes are used to remove soil and clay and expose quartz veins, which are then worked using hand tools. Care must be taken to avoid sudden temperature changes that may damage the crystals.[66][67]

## Related silica minerals

File:P-T Diagram for SiO2.svgPressure-temperature diagram showing the stability ranges for the two forms of quartz and some other forms of silica[68]

Tridymite and cristobalite are high-temperature polymorphs of SiO2 that occur in high-silica volcanic rocks. Coesite is a denser polymorph of SiO2 found in some meteorite impact sites and in metamorphic rocks formed at pressures greater than those typical of the Earth's crust. Stishovite is a yet denser and higher-pressure polymorph of SiO2 found in some meteorite impact sites.[16]: 201–202 Moganite is a monoclinic polymorph. Lechatelierite is an amorphous silica glass SiO2 which is formed by lightning strikes in quartz sand.[69]

## Safety

As quartz is a form of silica, it is a possible cause for concern in various workplaces. Cutting, grinding, chipping, sanding, drilling, and polishing natural and manufactured stone products can release hazardous levels of very small, crystalline silica dust particles into the air that workers breathe.[70] Crystalline silica of respirable size is a recognized human carcinogen and may lead to other diseases of the lungs such as silicosis and pulmonary fibrosis.[71][72]

## Synthetic and artificial treatments

A synthetic quartz crystal grown by the hydrothermal method, about 19 centimetres (7.5 in) long and weighing about 127 grams (4.5 oz)

Not all varieties of quartz are naturally occurring. Some clear quartz crystals can be treated using heat or gamma irradiation to induce color where it would not otherwise have occurred naturally. Susceptibility to such treatments depends on the location from which the quartz was mined.[73] Prasiolite, an olive-colored material, is produced by heat treatment;[74] natural prasiolite has also been observed in Lower Silesia in Poland.[75] Although citrine occurs naturally, the majority is the result of heat-treating amethyst or smoky quartz.[74] Carnelian has been heat-treated to deepen its color since prehistoric times.[76] Because natural quartz is often twinned, synthetic quartz is produced for use in industry. Large, flawless single crystals are synthesized in an autoclave via the hydrothermal process.[77][8][78][79] Like other crystals, quartz may be coated with metal vapors to give it an attractive sheen.[80][81]

## Uses

Quartz is the most common material identified as the mystical substance maban in Australian Aboriginal mythology. It is found regularly in passage tomb cemeteries in Europe in a burial context, such as Newgrange or Carrowmore in Ireland. Quartz was also used in prehistoric Ireland, as well as many other countries, for stone tools; both vein quartz and rock crystal were knapped as part of the lithic technology of prehistoric peoples.[82]

While jade has been the most prized semi-precious stone for carving in East Asia and pre-Columbian America since earliest times, in Europe and the Middle East different varieties of quartz were the most commonly used for the various types of jewelry and hardstone carving, including engraved gems and cameo gems, rock crystal vases, and extravagant vessels. The tradition continued to produce highly valued objects until the mid-19th century, when it largely fell from fashion except in jewelry. Cameo technique exploits the bands of color in onyx and other varieties.

Efforts to synthesize quartz began in the mid-19th century as scientists attempted to create minerals under laboratory conditions that mimicked the conditions in which the minerals formed in nature. German geologist Karl Emil von Schafhäutl (1803–1890) was the first person to synthesize quartz when in 1845 he created microscopic quartz crystals in a pressure cooker.[83] However, the quality and size of the crystals that were produced by these early efforts were poor.[84]

Elemental impurity incorporation strongly influences the ability to process and utilize quartz. Naturally occurring quartz crystals of extremely high purity, necessary for the crucibles and other equipment used for growing perfect large silicon boules to be sliced into silicon wafers in the semiconductor industry, are expensive and rare. These high-purity quartz are defined as containing less than 50 ppm of impurity elements.[85] A major mining location for high-purity quartz is the Spruce Pine Mining District in Spruce Pine, North Carolina, United States.[86] Quartz may also be found in Caldoveiro Peak in Asturias, Spain.[87]

By the 1930s, the electronics industry had become dependent on quartz crystals. The only source of suitable crystals was Brazil; however, World War II disrupted supplies from Brazil, so nations attempted to synthesize quartz on a commercial scale. German mineralogist Richard Nacken (1884–1971) achieved some success during the 1930s and 1940s.[88] After the war, many laboratories attempted to grow large quartz crystals. In the United States, the U.S. Army Signal Corps contracted with Bell Laboratories and with the Brush Development Company of Cleveland, Ohio to synthesize crystals following Nacken's lead.[89][90] (Prior to World War II, Brush Development produced piezoelectric crystals for record players.) By 1948, Brush Development had grown crystals that were 1.5 inches (3.8 cm) in diameter, the largest at that time.[91][92] By the 1950s, hydrothermal synthesis techniques were producing synthetic quartz crystals on an industrial scale, and today virtually all the quartz crystal used in the modern electronics industry is synthetic.[79]

An early use of the piezoelectricity of quartz crystals was in phonograph pickups. One of the most common piezoelectric uses of quartz today is as a crystal oscillator. Also called a quartz oscillator or resonator, it was first developed by Walter Guyton Cady in 1921.[93][94] George Washington Pierce designed and patented quartz crystal oscillators in 1923.[95][96][97] The quartz clock is a familiar device using the mineral; it is simply a clock that uses a quartz oscillator as its time reference. Warren Marrison created the first quartz oscillator clock based on the work of Cady and Pierce in 1927.[98] The resonant frequency of a quartz crystal oscillator is changed by mechanically loading it, and this principle is used for very accurate measurements of very small mass changes in the quartz crystal microbalance and in thin-film thickness monitors.[99]

* Rock crystal jug with cut festoon decoration by a Milan workshop from the second half of the 16th century, National Museum, Warsaw. Milan, apart from Prague and Florence, was the main Renaissance centre for crystal cutting.[100]

* Synthetic quartz crystals produced in the autoclave shown in Western Electric's pilot hydrothermal quartz plant in 1959

* Fatimid ewer in carved rock crystal (clear quartz) with gold lid, c. 1000

Almost all the industrial demand for quartz crystal (used primarily in electronics) is met with synthetic quartz produced by the hydrothermal process. However, synthetic crystals are less prized for use as gemstones.[101] The popularity of crystal healing has increased the demand for natural quartz crystals, which are now often mined in developing countries using primitive mining methods, sometimes involving child labor.[102]

## See also

* Fused quartz
* List of minerals
* Quartz fiber
* Quartz reef mining
* Quartzolite
* Shocked quartz

## References

1. ↑ 1.0 1.1 1.2 Deer, 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.
2. ↑ 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.
3. ↑ Kihara, K. (1990). "An X-ray study of the temperature dependence of the quartz structure". European Journal of Mineralogy 2 (1): 63–77. doi:10.1127/ejm/2/1/0063. Bibcode: 1990EJMin...2...63K.
4. ↑ Berry, R. W., et al. “Quartz Cleavage and Quick Clays.” Science, vol. 184, no. 4133, 12 Apr. 1974, pp. 183–184, https://doi.org/10.1126/science.184.4133.183. Accessed 19 May 2025.
5. ↑ Quartz . Mindat.org. Retrieved 2013-03-07.
6. ↑ "Quartz". Handbook of Mineralogy. III (Halides, Hydroxides, Oxides). Chantilly, VA: Mineralogical Society of America. 29 January 1990. ISBN 0962209724. http://rruff.geo.arizona.edu/doclib/hom/quartz.pdf. Retrieved 21 October 2009.
7. ↑ Quartz . Webmineral.com. Retrieved 2013-03-07.
8. ↑ 8.0 8.1 8.2 8.3 8.4 8.5 Hurlbut, Cornelius S.; Klein, Cornelis (1985). Manual of Mineralogy (20 ed.). Wiley. ISBN 0-471-80580-7. https://archive.org/details/manualofmineralo00klei.
9. ↑ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine 85 (3): 291–320. doi:10.1180/mgm.2021.43. Bibcode: 2021MinM...85..291W.
10. ↑ "Quartz". Merriam-Webster.com Dictionary. https://www.merriam-webster.com/dictionary/quartz.
11. ↑ "DWDS – Quarz" (in de). https://www.dwds.de/wb/Quarz.
12. ↑ "Quartz | Definition of quartz by Lexico". https://en.oxforddictionaries.com/definition/quartz.
13. ↑ Mineral Atlas[Usurped!], Queensland University of Technology. Mineralatlas.com. Retrieved 2013-03-07.
14. ↑ 14.0 14.1 Tomkeieff, S.I. (1942). "On the origin of the name 'quartz'". Mineralogical Magazine 26 (176): 172–178. doi:10.1180/minmag.1942.026.176.04. Bibcode: 1942MinM...26..172T. http://www.minersoc.org/pages/Archive-MM/Volume_26/26-176-172.pdf. Retrieved 12 August 2015.
15. ↑ Morgado, Antonio; Lozano, José Antonio; García Sanjuán, Leonardo; Triviño, Miriam Luciañez; Odriozola, Carlos P.; Irisarri, Daniel Lamarca; Flores, Álvaro Fernández (December 2016). "The allure of rock crystal in Copper Age southern Iberia: Technical skill and distinguished objects from Valencina de la Concepción (Seville, Spain)". Quaternary International 424: 232–249. doi:10.1016/j.quaint.2015.08.004. Bibcode: 2016QuInt.424..232M.
16. ↑ 16.0 16.1 16.2 16.3 Nesse, William D. (2000). Introduction to mineralogy. New York: Oxford University Press. ISBN 9780195106916.
17. ↑ Pliny the Elder, The Natural History, Book 37, Chapter 9. Available on-line at: Perseus.Tufts.edu .
18. ↑ Tutton, A.E. (1910). "Rock crystal: its structure and uses". RSA Journal 59: 1091.
19. ↑ Nicolaus Steno (Latinized name of Niels Steensen) with John Garrett Winter, trans.. The Prodromus of Nicolaus Steno's Dissertation Concerning a Solid Body Enclosed by Process of Nature Within a Solid (New York, New York: Macmillan Co., 1916). On page 272 , Steno states his law of constancy of interfacial angles: "Figures 5 and 6 belong to the class of those which I could present in countless numbers to prove that in the plane of the axis both the number and the length of the sides are changed in various ways without changing the angles; … "
20. ↑ "Quartz-beta". Hudson Institute of Mineralogy. https://www.mindat.org/min-7395.html.
21. ↑ Crystal Data, Determinative Tables, ACA Monograph No. 5, American Crystallographic Association, 1963
22. ↑ Johnson, Scott E.; Song, Won Joon; Cook, Alden C.; Vel, Senthil S.; Gerbi, Christopher C. (2021-01-01). "The quartz α↔β phase transition: Does it drive damage and reaction in continental crust?". Earth and Planetary Science Letters 553. doi:10.1016/j.epsl.2020.116622. ISSN 0012-821X. Bibcode: 2021E&PSL.55316622J.
23. ↑ Knapek, Michal; Húlan, Tomáš; Minárik, Peter; Dobroň, Patrik; Štubňa, Igor; Stráská, Jitka; Chmelík, František (January 2016). "Study of microcracking in illite-based ceramics during firing". Journal of the European Ceramic Society 36 (1): 221–226. doi:10.1016/j.jeurceramsoc.2015.09.004.
24. ↑ Tomás, R.; Cano, M.; Pulgarín, L. F.; Brotóns, V.; Benavente, D.; Miranda, T.; Vasconcelos, G. (2021-11-01). "Thermal effect of high temperatures on the physical and mechanical properties of a granite used in UNESCO World Heritage sites in north Portugal". Journal of Building Engineering 43. doi:10.1016/j.jobe.2021.102823. ISSN 2352-7102. https://linkinghub.elsevier.com/retrieve/pii/S2352710221006811.
25. ↑ Johnson, Scott E.; Song, Won Joon; Cook, Alden C.; Vel, Senthil S.; Gerbi, Christopher C. (January 2021). "The quartz α↔β phase transition: Does it drive damage and reaction in continental crust?". Earth and Planetary Science Letters 553. doi:10.1016/j.epsl.2020.116622. Bibcode: 2021E&PSL.55316622J.
26. ↑ Sinkankas, John (1964). Mineralogy for amateurs.. Princeton, N.J.: Van Nostrand. pp. 443–447. ISBN 0442276249.
27. ↑ Tarr, W. A (1929). "Doubly terminated quartz crystals occurring in gypsum". American Mineralogist 14 (1): 19–25. https://pubs.geoscienceworld.org/msa/ammin/article-abstract/14/1/19/535468. Retrieved 7 April 2021.
28. ↑ "Quartz: The gemstone Quartz information and pictures" (in en-US). http://www.minerals.net/gemstone/quartz_gemstone.aspx.
29. ↑ 29.0 29.1 29.2 Akhavan, Amir C. (4 November 2011). "Types of Quartz". http://www.quartzpage.de/gen_types.html.
30. ↑ 30.0 30.1 30.2 "Chalcedony". Hudson Institute of Mineralogy. https://www.mindat.org/min-960.html.
31. ↑ Heaney, Peter J. (1994). "Structure and Chemistry of the low-pressure silica polymorphs". Reviews in Mineralogy and Geochemistry 29 (1): 1–40. http://rimg.geoscienceworld.org/cgi/content/abstract/29/1/1. Retrieved 26 October 2009.
32. ↑ 32.0 32.1 "Quartz Gemstone and Jewelry Information: Natural Quartz - GemSelect". https://www.gemselect.com/gem-info/quartz/quartz-info.php.
33. ↑ "Agate". Hudson Institute of Mineralogy. https://www.mindat.org/min-51.html.
34. ↑ Pabian, Roger; Jackson, Brian; Tandy, Peter; Cromartie, John (2016). Agates: Treasures of the Earth. Firefly Books. ISBN 978-1-77085-644-8.
35. ↑ "Amethyst". Hudson Institute of Mineralogy. https://www.mindat.org/min-198.html.
36. ↑ Lehmann, G.; Moore, W. J. (20 May 1966). "Color Center in Amethyst Quartz". Science 152 (3725): 1061–1062. doi:10.1126/science.152.3725.1061. PMID 17754816. Bibcode: 1966Sci...152.1061L.
37. ↑ "Ametrine". https://www.mindat.org/min-7606.html.
38. ↑ "Quartz (var. ametrine) | Smithsonian National Museum of Natural History" (in en). https://naturalhistory.si.edu/explore/collections/geogallery/10002876.
39. ↑ Ralph, Jolyon; Ralph, Katya. "Carnelian gemstone information". https://www.gemdat.org/gem-9333.html.
40. ↑ "Citrine Value, Price, and Jewelry Information - International Gem Society" (in en-US). International Gem Society. https://www.gemsociety.org/article/citrine-jewelry-gemstone-information/.
41. ↑ "Citrine". https://www.mindat.org/min-1054.html.
42. ↑ "Burnt amethyst". https://www.mindat.org/min-40451.html.
43. ↑ "Boy (7) strikes it lucky by finding one of the world’s rarest minerals near his home in Cork". https://www.irishtimes.com/environment/2026/01/10/boy-7-strikes-it-lucky-by-finding-one-of-the-worlds-rarest-minerals-near-his-home-in-cork/.
44. ↑ "Cotterite". https://www.mindat.org/min-9938.html.
45. ↑ Roycroft, P.D. (2016). "Cotterite: Historical review; extant specimens; etymology of 'Cotterite' and the genealogy of 'Miss Cotter'; new observations on the Cotterite texture". Irish Journal of Earth Sciences 34: 45–78. doi:10.3318/ijes.2016.34.45.
46. ↑ "The Gemstone Dumortierite". Minerals.net. http://www.minerals.net/gemstone/dumortierite_gemstone.aspx.
47. ↑ Oldershaw, Cally (2003). Firefly Guide to Gems. Firefly Books. pp. 100. ISBN 9781552978146. https://archive.org/details/fireflyguidetoge0000olde. Retrieved 19 February 2017.
48. ↑ Friedman, Herschel. "THE GEMSTONE DUMORTIERITE". https://www.minerals.net/gemstone/dumortierite_gemstone.aspx.
49. ↑ Hurrell, Karen; Johnson, Mary L. (2016). Gemstones: A Complete Color Reference for Precious and Semiprecious Stones of the World. Book Sales. p. 97. ISBN 978-0-7858-3498-4. https://books.google.com/books?id=KLSTDgAAQBAJ&pg=PA97.
50. ↑ Milky quartz at Mineral Galleries . Galleries.com. Retrieved 2013-03-07.
51. ↑ Klemme, S.; Berndt, J.; Mavrogonatos, C.; Flemetakis, S.; Baziotis, I.; Voudouris, P.; Xydous, S. (2018). "On the Color and Genesis of Prase (Green Quartz) and Amethyst from the Island of Serifos, Cyclades, Greece". Minerals 8 (11): 487. doi:10.3390/min8110487. Bibcode: 2018Mine....8..487K.
52. ↑ "Prase". https://www.mindat.org/min-6703.html.
53. ↑ "Prasiolite". quarzpage.de. 28 October 2009. http://www.quartzpage.de/prasiolite.html.
54. ↑ "Prasiolite". Hudson Institute of Mineralogy. https://www.mindat.org/min-40112.html.
55. ↑ "Rose Quartz". Hudson Institute of Mineralogy. https://www.mindat.org/show.php?id=3456.
56. ↑ Akhavan, Amir C.. "Rose Quartz". http://www.quartzpage.de/rose.html.
57. ↑ Akhavan, Amir C.. "Pink Quartz". http://www.quartzpage.de/pink.html.
58. ↑ Fridrichová, Jana; Bačík, Peter; Illášová, Ľudmila; Kozáková, Petra; Škoda, Radek; Pulišová, Zuzana; Fiala, Anton (July 2016). "Raman and optical spectroscopic investigation of gem-quality smoky quartz crystals". Vibrational Spectroscopy 85: 71–78. doi:10.1016/j.vibspec.2016.03.028. Bibcode: 2016VibSp..85...71F.
59. ↑ Uchino, Kenji, ed (2017). "Chapter 5 – Quartz-Based Piezoelectric Materials". Advanced Piezoelectric Materials. Woodhead Publishing in Materials (2nd ed.). Woodhead Publishing. pp. 197–233. doi:10.1016/B978-0-08-102135-4.00005-9. ISBN 9780081021354.
60. ↑ Curie, Jacques; Curie, Pierre (1880). "Développement par compression de l'électricité polaire dans les cristaux hémièdres à faces inclinées". Bulletin de la Société minéralogique de France 3 (4): 90–93. doi:10.3406/bulmi.1880.1564. https://babel.hathitrust.org/cgi/pt?id=uc1.b3616891&view=1up&seq=100. . Reprinted in: Curie, Jacques; Curie, Pierre (1880). "Développement, par pression, de l'électricité polaire dans les cristaux hémièdres à faces inclinées". Comptes rendus 91: 294–295. http://gallica.bnf.fr/ark:/12148/bpt6k30485/f296.image. Retrieved 17 December 2013.
61. ↑ Curie, Jacques; Curie, Pierre (1880). "Sur l'électricité polaire dans les cristaux hémièdres à faces inclinées". Comptes rendus 91: 383–386. http://gallica.bnf.fr/ark:/12148/bpt6k30485/f385.image. Retrieved 17 December 2013.
62. ↑ 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. https://books.google.com/books?id=hDt5A2-km_wC.
63. ↑ Boggs, Sam (2006). Principles of sedimentology and stratigraphy (4th ed.). Upper Saddle River, N.J.: Pearson Prentice Hall. p. 130. ISBN 0131547283.
64. ↑ Jahns, Richard H. (1953). "The genesis of pegmatites: I. Occurrence and origin of giant crystals". American Mineralogist 38 (7–8): 563–598. https://pubs.geoscienceworld.org/msa/ammin/article-abstract/38/7-8/563/539244. Retrieved 7 April 2021.
65. ↑ Rickwood, P. C. (1981). "The largest crystals". American Mineralogist 66: 885–907 (903). http://www.minsocam.org/ammin/AM66/AM66_885.pdf. Retrieved 7 March 2013.
66. ↑ McMillen, Allen. "Quartz Mining". Central Arkansas Library System. https://encyclopediaofarkansas.net/entries/quartz-mining-1173/.
67. ↑ Eleanor McKenzie (25 April 2017). "How Is Quartz Extracted?". https://sciencing.com/quartz-extracted-8700692.html.
68. ↑ "Mineral Science" by Cornelis Klein; ISBN 0-471-25177-1
69. ↑ "Lechatelierite". https://www.mindat.org/min-2363.html.
70. ↑ Hazard Alert - Worker Exposure to Silica during Countertop Manufacturing, Finishing and Installation. DHHS (NIOSH). p. 2. https://www.osha.gov/Publications/OSHA3768.pdf. Retrieved 27 November 2019.
71. ↑ "Silica (crystalline, respirable)". California Office of Environmental Health Hazard Assessment. https://oehha.ca.gov/chemicals/silica-crystalline-respirable.
72. ↑ Arsenic, Metals, Fibres and Dusts. A Review of Human Carcinogens (100C ed.). International Agency for Research on Cancer. 2012. pp. 355–397. ISBN 978-92-832-1320-8. https://www.ncbi.nlm.nih.gov/books/NBK304375/pdf/Bookshelf_NBK304375.pdf. Retrieved 27 November 2019.
73. ↑ Liccini, Mark. "Treating Quartz to Create Color - International Gem Society IGS" (in en-US). International Gem Society IGS. http://www.gemsociety.org/article/treating-quartz-color/.
74. ↑ 74.0 74.1 Henn, U.; Schultz-Güttler, R. (2012). "Review of some current coloured quartz varieties". J. Gemmol 33 (1): 29–43. doi:10.15506/JoG.2012.33.1.29. Bibcode: 2012JGem...33...29H. https://gem-a.com/images/Documents/JoG/JoG2012_33_1-4.pdf#page=31. Retrieved 7 April 2021.
75. ↑ Platonov, Alexej N.; Szuszkiewicz, Adam (1 June 2015). "Green to blue-green quartz from Rakowice Wielkie (Sudetes, south-western Poland) – a re-examination of prasiolite-related color varieties of quartz". Mineralogia 46 (1–2): 19–28. doi:10.1515/mipo-2016-0004. Bibcode: 2015Miner..46...19P.
76. ↑ Groman-Yaroslavski, Iris; Bar-Yosef Mayer, Daniella E. (June 2015). "Lapidary technology revealed by functional analysis of carnelian beads from the early Neolithic site of Nahal Hemar Cave, southern Levant". Journal of Archaeological Science 58: 77–88. doi:10.1016/j.jas.2015.03.030. Bibcode: 2015JArSc..58...77G.
77. ↑ Walker, A. C. (August 1953). "Hydrothermal Synthesis of Quartz Crystals". Journal of the American Ceramic Society 36 (8): 250–256. doi:10.1111/j.1151-2916.1953.tb12877.x.
78. ↑ "san thach anh kobler" (in en). 2016-07-04. https://sankobler.com/.
79. ↑ 79.0 79.1 Buisson, X.; Arnaud, R. (February 1994). "Hydrothermal growth of quartz crystals in industry. Present status and evolution". Le Journal de Physique IV 04 (C2): C2–25–C2-32. doi:10.1051/jp4:1994204. https://hal.archives-ouvertes.fr/jpa-00252472/file/ajp-jp4199404C204.pdf.
80. ↑ O'Donoghue, Michael; Robert, Webster (January 2006) (in en). Gems: Their Sources, Descriptions and Identification. Butterworth-Heinemann. ISBN 978-0-7506-5856-0. https://books.google.com/books?id=ZwcM5H-wHNoC&q=""2aqua+aura""2+-healing&pg=PT28.
81. ↑ Team, Geology In. "What is Aura Rainbow Quartz and How Is It Made?" (in en). https://www.geologyin.com/2017/06/how-is-aura-rainbow-quartz-made.html.
82. ↑ Driscoll, Killian (2010). quartz lithic technology history quartz lithic research Ireland chapter 3 (PhD thesis). University College Dublin. Archived from the original on 2017-06-25.
83. ↑ von Schafhäutl, Karl Emil (10 April 1845). "Die neuesten geologischen Hypothesen und ihr Verhältniß zur Naturwissenschaft überhaupt (Fortsetzung)". Gelehrte Anzeigen (München: im Verlage der königlichen Akademie der Wissenschaften, in Commission der Franz'schen Buchhandlung) 20 (72): 577–584. OCLC 1478717. https://archive.org/stream/gelehrteanzeige06wissgoog#page/n298/mode/1up. From page 578: 5) Bildeten sich aus Wasser, in welchen ich im Papinianischen Topfe frisch gefällte Kieselsäure aufgelöst hatte, beym Verdampfen schon nach 8 Tagen Krystalle, die zwar mikroscopisch, aber sehr wohl erkenntlich aus sechseitigen Prismen mit derselben gewöhnlichen Pyramide bestanden. ( 5) There formed from water in which I had dissolved freshly precipitated silicic acid in a Papin pot [i.e., pressure cooker], after just 8 days of evaporating, crystals, which albeit were microscopic but consisted of very easily recognizable six-sided prisms with their usual pyramids.)
84. ↑ Byrappa, K. and Yoshimura, Masahiro (2001) Handbook of Hydrothermal Technology. Norwich, New York: Noyes Publications. ISBN 008094681X. Chapter 2: History of Hydrothermal Technology.
85. ↑ Götze, Jens; Pan, Yuanming; Müller, Axel (October 2021). "Mineralogy and mineral chemistry of quartz: A review" (in en). Mineralogical Magazine 85 (5): 639–664. doi:10.1180/mgm.2021.72. ISSN 0026-461X. Bibcode: 2021MinM...85..639G.
86. ↑ Nelson, Sue (2009-08-02). "Silicon Valley's secret recipe". BBC News. http://news.bbc.co.uk/2/hi/technology/8178580.stm.
87. ↑ "Caldoveiro Mine, Tameza, Asturias, Spain". https://www.mindat.org/loc-122679.html.
88. ↑ Nacken, R. (1950) "Hydrothermal Synthese als Grundlage für Züchtung von Quarz-Kristallen" (Hydrothermal synthesis as a basis for the production of quartz crystals), Chemiker Zeitung, 74 : 745–749.
89. ↑ Hale, D. R. (1948). "The Laboratory Growing of Quartz". Science 107 (2781): 393–394. doi:10.1126/science.107.2781.393. PMID 17783928. Bibcode: 1948Sci...107..393H.
90. ↑ Lombardi, M. (2011). "The evolution of time measurement, Part 2: Quartz clocks [Recalibration"]. IEEE Instrumentation & Measurement Magazine 14 (5): 41–48. doi:10.1109/MIM.2011.6041381. http://tf.nist.gov/general/pdf/2534.pdf. Retrieved 30 March 2013.
91. ↑ "Record crystal", Popular Science, 154 (2) : 148 (February 1949).
92. ↑ Brush Development's team of scientists included: Danforth R. Hale, Andrew R. Sobek, and Charles Baldwin Sawyer (1895–1964). The company's U.S. patents included:
* Sobek, Andrew R. "Apparatus for growing single crystals of quartz", U.S. Patent 2,674,520; filed: 11 April 1950; issued: 6 April 1954.
* Sobek, Andrew R. and Hale, Danforth R. "Method and apparatus for growing single crystals of quartz", U.S. Patent 2,675,303; filed: 11 April 1950; issued: 13 April 1954.
* Sawyer, Charles B. "Production of artificial crystals", U.S. Patent 3,013,867; filed: 27 March 1959; issued: 19 December 1961. (This patent was assigned to Sawyer Research Products of Eastlake, Ohio.)
93. ↑ Cady, W. G. (1921). "The piezoelectric resonator". Physical Review 17: 531–533. doi:10.1103/PhysRev.17.508. https://zenodo.org/record/2523161.
94. ↑ "The Quartz Watch – Walter Guyton Cady". The Lemelson Center, National Museum of American History, Smithsonian Institution. http://invention.smithsonian.org/centerpieces/quartz/inventors/cady.html.
95. ↑ Pierce, G. W. (1923). "Piezoelectric crystal resonators and crystal oscillators applied to the precision calibration of wavemeters". Proceedings of the American Academy of Arts and Sciences 59 (4): 81–106. doi:10.2307/20026061.
96. ↑ Pierce, George W. "Electrical system", U.S. Patent 2,133,642, filed: 25 February 1924; issued: 18 October 1938.
97. ↑ "The Quartz Watch – George Washington Pierce". The Lemelson Center, National Museum of American History, Smithsonian Institution. http://invention.smithsonian.org/centerpieces/quartz/inventors/pierce.html.
98. ↑ "The Quartz Watch – Warren Marrison". The Lemelson Center, National Museum of American History, Smithsonian Institution. http://invention.smithsonian.org/centerpieces/quartz/inventors/clock.html.
99. ↑ "Verwendung von Schwingquarzen zur Wägung dünner Schichten und zur Mikrowägung" (in de). Zeitschrift für Physik (Springer-Verlag) 155 (2): 206–222. April 1959. doi:10.1007/BF01337937. ISSN 0044-3328. Bibcode: 1959ZPhy..155..206S. http://jmfriedt.sequanux.org/t/sauerbrey.pdf. Retrieved 2019-02-26. (NB. This was partially presented at Physikertagung in Heidelberg in October 1957.)
100. ↑ The International Antiques Yearbook. Studio Vista Limited. 1972. p. 78. https://books.google.com/books?id=BVcvAQAAIAAJ. "Apart from Prague and Florence, the main Renaissance centre for crystal cutting was Milan."
101. ↑ "Hydrothermal Quartz". GemSelect.com. https://www.gemselect.com/other-info/synthetic-quartz.php.
102. ↑ McClure, Tess (2019-09-17). "Dark crystals: the brutal reality behind a booming wellness craze" (in en-GB). The Guardian. ISSN 0261-3077. https://www.theguardian.com/lifeandstyle/2019/sep/17/healing-crystals-wellness-mining-madagascar.

## External links

* Quartz varieties, properties, crystal morphology. Photos and illustrations
* Gilbert Hart, "Nomenclature of Silica", American Mineralogist, Volume 12, pp. 383–395. 1927
* "The Quartz Watch – Inventors". The Lemelson Center, National Museum of American History, Smithsonian Institution. http://invention.smithsonian.org/centerpieces/quartz/inventors/index.html.
* Terminology used to describe the characteristics of quartz crystals when used as oscillators
* Quartz use as prehistoric stone tool raw material

Template:Mohs

* v
* t
* e

Silica minerals

Crystalline|

* Coesite
* Cristobalite
* Keatite
* Moganite
* Quartz
* Seifertite
* Stishovite
* Tridymite

Cryptocrystalline|

* Chalcedony
* Chert
* Flint
* Jasper

Amorphous|

* Fulgurite
* Lechatelierite
* Opal

Miscellaneous|

* Tiger's eye

Notable varieties|

| Chalcedony|

* Agate
* Carnelian
* Chrysoprase
* Heliotrope
* Onyx

|

Opal|

* Fiorite
* Geyserite

Quartz|

* Amethyst
* Ametrine
* Herkimer diamond
* Smoky quartz
* Shocked quartz
* Prasiolite

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Quartz. Read more

|

Retrieved from "https://handwiki.org/wiki/index.php?title=Chemistry:Quartz&oldid=4309222"
*[c.]: circa
*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template