HOME

TheInfoList




Quartz is a hard,
crystalline A crystal or crystalline solid is a solid Solid is one of the four fundamental states of matter (the others being liquid, gas and plasma). The molecules in a solid are closely packed together and contain the least amount of kinet ...

crystalline
mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...

mineral
composed of silica (
silicon dioxide Silicon dioxide, also known as silica, is an oxide of rutile. Ti(IV) centers are grey; oxygen centers are red. Notice that oxygen forms three bonds to titanium and titanium forms six bonds to oxygen. An oxide () is a chemical compound that con ...
). The atoms are linked in a continuous framework of SiO4 silicon-oxygen
tetrahedra In geometry Geometry (from the grc, γεωμετρία; ' "earth", ' "measurement") is, with , one of the oldest branches of . It is concerned with properties of space that are related with distance, shape, size, and relative position ...
, with each oxygen being shared between two tetrahedra, giving an overall
chemical formula A chemical formula is a way of presenting information about the chemical proportions of atom An atom is the smallest unit of ordinary matter In classical physics and general chemistry, matter is any substance that has mass and takes ...
of SiO2. Quartz is the second most abundant
mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...

mineral
in
Earth Earth is the third planet from the Sun and the only astronomical object known to harbour and support life. 29.2% of Earth's surface is land consisting of continents and islands. The remaining 70.8% is Water distribution on Earth, covered wi ...

Earth
's
continental crust Continental crust is the layer of igneous Igneous rock (derived from the Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the ...
, behind
feldspar Feldspars are a group of rock-forming aluminium Aluminium (aluminum in and ) is a with the  Al and  13. Aluminium has a density lower than those of other common , at approximately one third that of . It has a great affinity ...
. Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are
chiral Chirality is a property of important in several branches of science. The word ''chirality'' is derived from the (''kheir''), "hand", a familiar chiral object. An object or a system is ''chiral'' if it is distinguishable from its ; that is, i ...

chiral
. The transformation from α-quartz to β-quartz takes place abruptly at . Since the transformation is accompanied by a significant change in volume, it can easily induce fracturing of ceramics or rocks passing through this temperature threshold. There are many different varieties of quartz, several of which are classified
gemstone A gemstone (also called a fine gem, jewel, precious stone, or semi-precious stone) is a piece of mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chem ...

gemstone
s. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of
jewelry Jewellery or jewelry consists of decorative items worn for personal adornment 150px, The principal adornment of these girls from the Bundu tribe in Sierra Leone is the adornment of bodies and faces with markings produced by the smearing on by ...

jewelry
and
hardstone carving Hardstone carving is a general term in art history and archaeology Archaeology or archeology is the study of human activity through the recovery and analysis Analysis is the process of breaking a complexity, complex topic or Substance t ...
s, especially in
Eurasia Eurasia () is the largest continent A continent is any of several large landmass A landmass, or land mass, is a large region In geography Geography (from Greek: , ''geographia'', literally "earth description") is a ...

Eurasia
. Quartz is the
mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...

mineral
defining the value of 7 on the
Mohs scale of hardness The Mohs scale of mineral hardness () is a qualitative ordinal scale Ordinal data is a categorical, statistical data type where the variables have natural, ordered categories and the distances between the categories is not known. These data ex ...
, a qualitative scratch method for determining the hardness of a material to abrasion.


Etymology

The word "quartz" is derived from the
German German(s) may refer to: Common uses * of or related to Germany * Germans, Germanic ethnic group, citizens of Germany or people of German ancestry * For citizens of Germany, see also German nationality law * German language The German la ...

German
word "Quarz", which had the same form in the first half of the 14th century in
Middle High German Middle High German (MHG; german: Mittelhochdeutsch (Mhd.)) is the term for the form of German German(s) may refer to: Common uses * of or related to Germany * Germans, Germanic ethnic group, citizens of Germany or people of German ancestry * ...
and in
East Central German East Central German or East Middle German (german: Ostmitteldeutsch) is the eastern, non-Franconian languages, Franconian Central German language, part of High German languages, High German. Present-day Standard German as a High German languages, ...
and which came from the Polish dialect term ''kwardy'', which corresponds to the Czech term ''tvrdý'' ("hard"). The
Ancient Greeks Ancient Greece ( el, Ἑλλάς, Hellás) was a civilization belonging to a period of History of Greece, Greek history from the Greek Dark Ages of the 12th–9th centuries BC to the end of Classical Antiquity, antiquity ( AD 600). This era was ...
referred to quartz as κρύσταλλος (''krustallos'') derived from the
Ancient Greek Ancient Greek includes the forms of the Greek language Greek ( el, label=Modern Greek Modern Greek (, , or , ''Kiní Neoellinikí Glóssa''), generally referred to by speakers simply as Greek (, ), refers collectively to the diale ...
''κρύος'' (''kruos'') meaning "icy cold", because some
philosopher A philosopher is someone who practices philosophy Philosophy (from , ) is the study of general and fundamental questions, such as those about Metaphysics, existence, reason, Epistemology, knowledge, Ethics, values, Philosophy of mind, mi ...

philosopher
s (including
Theophrastus Theophrastus (; grc-gre, Θεόφραστος ; c. 371c. 287 BC), a Greek native of Eresos Eresos (; el, Ερεσός; grc, Ἔρεσος) and its twin beach village Skala Eresou are located in the southwest part of the Greek island of Le ...

Theophrastus
) apparently believed the mineral to be a form of
supercooled Supercooling, also known as undercooling, is the process of lowering the temperature of a liquid A liquid is a nearly incompressible In fluid mechanics or more generally continuum mechanics, incompressible flow (isochoric process, isoc ...
ice. Today, the term ''
rock crystal Quartz is a hard, crystalline mineral composed of silicon and oxygen atoms. The atoms are linked in a continuous framework of SiO4 silicon-oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tetrahedra, g ...

rock crystal
'' is sometimes used as an alternative name for transparent coarsely crystalline quartz.


Crystal habit and structure

Quartz belongs to the
trigonal crystal system In crystallography, the hexagonal crystal family is one of the six crystal family, crystal families, which includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the trigo ...
at room temperature, and to the
hexagonal crystal system In crystallography, the hexagonal crystal family is one of the six crystal family, crystal families, which includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the tri ...
above . The ideal crystal shape is a six-sided
prism A prism An optical prism is a transparent optics, optical element with flat, polished surfaces that refraction, refract light. At least one surface must be angled—elements with two parallel surfaces are not prisms. The traditional geometrical ...
terminating with six-sided
pyramid A pyramid (from el, πυραμίς ') is a structure A structure is an arrangement and organization of interrelated elements in a material object or system A system is a group of Interaction, interacting or interrelated elements that act ...

pyramid
s at each end. In
nature Nature, in the broadest sense, is the natural, physical, material world or universe The universe ( la, universus) is all of space and time and their contents, including planets, stars, galaxy, galaxies, and all other forms of matter an ...

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. Well-formed crystals typically form as a druse (a layer of crystals lining a void), of which quartz
geode A geode (; ) is a geological Geology (from the Ancient Greek γῆ, ''gē'' ("earth") and -λoγία, ''-logia'', ("study of", "discourse")) is an Earth science concerned with the solid Earth, the rock (geology), rocks of which it is compos ...

geode
s are particularly fine examples. 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 Gypsum is a soft sulfate mineral The sulfate minerals are a class of mineral In geology Geology (from the Ancient Greek γῆ, ''gē'' ("earth") and -λoγία, ''-logia'', ("study of", "discourse")) is an Earth science concerned with ...

gypsum
. α-quartz crystallizes in the trigonal crystal system,
space group In mathematics Mathematics (from Greek: ) includes the study of such topics as numbers (arithmetic and number theory), formulas and related structures (algebra), shapes and spaces in which they are contained (geometry), and quantities and ...
''P''3121 or ''P''3221 (space group 152 or 154 resp.) depending on the chirality. Above , α-quartz in ''P''3121 becomes the more symmetric hexagonal ''P''6422 (space group 181), and α-quartz in ''P''3221 goes to space group ''P''6222 (no. 180). 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. File:Α-Quartz.svg, Crystal structure of α-quartz (red balls are oxygen, grey are silicon) File:Β-Quartz.svg, β-quartz


Varieties (according to microstructure)

Although many of the varietal names historically arose from the color of the mineral, current scientific naming schemes refer primarily to the microstructure of the mineral. Color is a secondary identifier for the cryptocrystalline minerals, although it is a primary identifier for the macrocrystalline varieties.


Varieties (according to color)

Pure quartz, traditionally called rock crystal or clear quartz, is colorless and
transparent Transparency, transparence or transparent most often refer to transparency and translucency, the physical property of allowing the transmission of light through a material. They may also refer to: Literal uses * Transparency (photography), a sti ...
or translucent, and has often been used for
hardstone carving Hardstone carving is a general term in art history and archaeology Archaeology or archeology is the study of human activity through the recovery and analysis Analysis is the process of breaking a complexity, complex topic or Substance t ...
s, such as the
Lothair Crystal The Lothair Crystal (also known as the Lothar Crystal or the Susanna Crystal) is an engraved gem from Lotharingia in northwest Europe, showing scenes of the Bible, biblical story of Susanna (Book of Daniel), Susanna, dating from 855–869. The Lot ...
. Common colored varieties include citrine, rose quartz, amethyst, smoky quartz, milky quartz, and others. 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 causing colors. The most important distinction between types of quartz is that of ''macrocrystalline'' (individual crystals visible to the unaided eye) and the
microcrystalline A microcrystalline material is a crystallized substance or rock that contains small crystals visible only through microscopic The microscopic scale (from , ''mikrós'', "small" and σκοπέω, ''skopéō'' "look") is the scale of objects and ...
or
cryptocrystalline Cryptocrystalline is a rock Rock most often refers to: * Rock (geology) A rock is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its Chemical compound, chemical ...
varieties ( aggregates of crystals visible only under high magnification). The cryptocrystalline varieties are either translucent or mostly opaque, while the transparent varieties tend to be macrocrystalline.
Chalcedony Chalcedony () is a cryptocrystalline form of silica, composed of very fine intergrowths of quartz and moganite. These are both silica minerals, but they differ in that quartz has a trigonal crystal structure, while moganite is monoclinic. Chalced ...

Chalcedony
is a cryptocrystalline form of silica consisting of fine intergrowths of both quartz, and its
monoclinic In crystallography Crystallography is the experimental science of determining the arrangement of atoms in crystalline solids (see crystal structure). The word "crystallography" is derived from the Greek language, Greek words ''crystallon'' " ...
polymorph
moganite Moganite is an oxide mineral with the chemical formula Si O2 (silicon dioxide Silicon dioxide, also known as silica, is an oxide of rutile. Ti(IV) centers are grey; oxygen centers are red. Notice that oxygen forms three bonds to titanium and ...

moganite
. Other opaque gemstone varieties of quartz, or mixed rocks including quartz, often including contrasting bands or patterns of color, are
agate Agate is a common rock formation, consisting of chalcedony and quartz as its primary components, consisting of a wide variety of colors. Agates are primarily formed within Volcanic rock, volcanic and Metamorphic rock, metamorphic rocks. The orn ...

agate
,
carnelian Carnelian (also spelled cornelian) is a brownish-red mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal stru ...

carnelian
or sard,
onyx Onyx primarily refers to the parallel banded variety of the silicate mineral Silicate minerals are rock-forming mineral In geology Geology (from the Ancient Greek γῆ, ''gē'' ("earth") and -λoγία, ''-logia'', ("study of", "dis ...

onyx
, heliotrope, and
jasper Jasper, an aggregate of microgranular quartz Quartz is a hard, crystalline mineral composed of silicon and oxygen atoms. The atoms are linked in a continuous framework of SiO4 silicon-oxygen Tetrahedral molecular geometry, tetrahedra, with ...

jasper
.


Amethyst

Amethyst Amethyst is a violet (color), violet variety of quartz. The name comes from the Koine Greek αμέθυστος ''amethystos'' from α- ''a-'', "not" and μεθύσκω (Ancient Greek) / μεθώ (Modern Greek), "intoxicate", a reference to ...

Amethyst
is a form of quartz that ranges from a bright vivid violet to dark or dull lavender shade. The world's largest deposits of amethysts can be found in Brazil, Mexico, Uruguay, Russia, France, Namibia and Morocco. Sometimes amethyst and citrine are found growing in the same crystal. It is then referred to as ametrine. An amethyst derives its color from traces of iron in its structure.


Blue quartz

Blue quartz contains inclusions of fibrous magnesio-riebeckite or
crocidolite Riebeckite is a sodium-rich member of the amphibole group of silicate minerals, chemical formula Na2(Fe2+3Fe3+2)Si8O22(OH)2. It forms a solid solution series with magnesioriebeckite. It crystallizes in the monoclinic system, usually as long pris ...
.


Dumortierite quartz

Inclusions of the mineral
dumortierite Dumortierite is a fibrous variably colored aluminium Aluminium (aluminum in American English, American and Canadian English) is a chemical element with the Symbol (chemistry), symbol Al and atomic number 13. Aluminium has a density ...
within quartz pieces often result in silky-appearing splotches with a
blue Blue is one of the three primary colours of pigments in painting and traditional colour theory In the visual arts The visual arts are art forms such as painting Painting is the practice of applying paint Paint is any pig ...
hue. Shades of
purple Purple is any of a variety of color Color (American English American English (AmE, AE, AmEng, USEng, en-US), sometimes called United States English or U.S. English, is the set of varieties of the English language native to the ...
or
grey Grey or gray (American English American English (AmE, AE, AmEng, USEng, en-US), sometimes called United States English or U.S. English, is the set of varieties of the English language native to the United States. Currently, American Eng ...
sometimes also are present. "Dumortierite quartz" (sometimes called "blue quartz") will sometimes feature contrasting light and dark color zones across the material. "Blue quartz" is a minor gemstone.


Citrine

Citrine is a variety of quartz whose color ranges from a pale yellow to brown due to a submicroscopic distribution of colloidal
ferric In chemistry, iron(III) refers to the chemical element, element iron in its +3 oxidation number, oxidation state. In salt (chemistry), ionic compounds (salts), such an atom may occur as a separate cation (positive ion) denoted by Fe3+. The adject ...

ferric
hydroxide impurities. Natural citrines are rare; most commercial citrines are heat-treated
amethyst Amethyst is a violet (color), violet variety of quartz. The name comes from the Koine Greek αμέθυστος ''amethystos'' from α- ''a-'', "not" and μεθύσκω (Ancient Greek) / μεθώ (Modern Greek), "intoxicate", a reference to ...

amethyst
s or
smoky quartz Smoky quartz is a brownish grey, translucent variety of quartz Quartz is a hard, crystalline A crystal or crystalline solid is a solid Solid is one of the four fundamental states of matter (the others being liquid, gas and ...

smoky quartz
es. However, a heat-treated amethyst will have small lines in the crystal, as opposed to a natural citrine's cloudy or smoky appearance. It is nearly impossible to differentiate between cut citrine and yellow
topaz Topaz ( ) is a silicate mineral Silicate minerals are rock-forming mineral In geology Geology (from the Ancient Greek γῆ, ''gē'' ("earth") and -λoγία, ''-logia'', ("study of", "discourse")) is an Earth science concerned with ...

topaz
visually, but they differ in
hardness Hardness (antonym: softness) is a measure of the resistance to localized plastic deformation In engineering, deformation refers to the change in size or shape of an object. ''Displacements'' are the ''absolute'' change in position of a point ...
. Brazil is the leading producer of citrine, with much of its production coming from the state of
Rio Grande do Sul Rio Grande do Sul (, , ; "Great River of the South") is a state State may refer to: Arts, entertainment, and media Literature * ''State Magazine'', a monthly magazine published by the U.S. Department of State * The State (newspaper), ''The St ...
. The name is derived from the Latin word ''citrina'' which means "yellow" and is also the origin of the word "
citron The citron (''Citrus medica'') is a large fragrant citrus fruit with a thick Peel (fruit), rind. It is one of the original citrus fruits from which all other citrus types developed through natural hybrid speciation or artificial Hybrid (biolog ...

citron
". Sometimes citrine and amethyst can be found together in the same crystal, which is then referred to as ametrine. Citrine has been referred to as the "merchant's stone" or "money stone", due to a superstition that it would bring prosperity. Citrine was first appreciated as a golden-yellow gemstone in Greece between 300 and 150 BC, during the Hellenistic Age. The yellow quartz was used prior to that to decorate jewelry and tools but it was not highly sought after.


Milky quartz

Milk quartz or milky quartz is the most common variety of crystalline quartz. The white color is caused by minute
fluid inclusions image:Inclumed.gif, 250px, Trapped in a time capsule the same size as the diameter of a human hair, the ore-forming liquid in this inclusion was so hot and contained so much dissolved solids that when it cooled, crystals of halite, sylvite, gypsum, ...
of gas, liquid, or both, trapped during crystal formation, making it of little value for optical and quality gemstone applications.


Rose quartz

Rose quartz is a type of quartz which exhibits a pale pink to rose red hue. The color is usually considered as due to trace amounts of
titanium Titanium is a chemical element In chemistry, an element is a pure Chemical substance, substance consisting only of atoms that all have the same numbers of protons in their atomic nucleus, nuclei. Unlike chemical compounds, chemical ele ...

titanium
,
iron Iron () is a chemical element In chemistry Chemistry is the study of the properties and behavior of . It is a that covers the that make up matter to the composed of s, s and s: their composition, structure, properties, behav ...

iron
, or
manganese Manganese is a chemical element In chemistry, an element is a pure Chemical substance, substance consisting only of atoms that all have the same numbers of protons in their atomic nucleus, nuclei. Unlike chemical compounds, chemical e ...

manganese
, in the material. Some rose quartz contains microscopic
rutile Rutile is an oxide mineral The oxide mineral class includes those mineral In geology Geology (from the Ancient Greek γῆ, ''gē'' ("earth") and -λoγία, ''-logia'', ("study of", "discourse")) is an Earth science concerned with the so ...

rutile
needles which produces an asterism in transmitted light. Recent
X-ray diffraction X-ray crystallography (XRC) is the experimental science determining the atomic and molecular structure of a crystal A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a ...

X-ray diffraction
studies suggest that the color is due to thin microscopic fibers of possibly
dumortierite Dumortierite is a fibrous variably colored aluminium Aluminium (aluminum in American English, American and Canadian English) is a chemical element with the Symbol (chemistry), symbol Al and atomic number 13. Aluminium has a density ...
within the quartz. Additionally, there is a rare type of pink quartz (also frequently called crystalline rose quartz) with color that is thought to be caused by trace amounts of
phosphate In chemistry, a phosphate is an anion, salt (chemistry), salt, functional group or ester derived from a phosphoric acids and phosphates, phosphoric acid. It most commonly means orthophosphate, a derivative of phosphoric acid, orthophosphoric a ...

phosphate
or
aluminium Aluminium (aluminum in and ) is a with the  Al and  13. Aluminium has a density lower than those of other common , at approximately one third that of . It has a great affinity towards , and of on the surface when exposed to air ...

aluminium
. The color in crystals is apparently photosensitive and subject to fading. The first crystals were found in a
pegmatite A pegmatite is an igneous rock showing a very coarse Texture (geology), texure, with large interlocking crystals usually greater in size than and sometimes greater than . Most pegmatites are composed of quartz, feldspar, and mica, having a si ...
found near Rumford,
Maine Maine () is a U.S. state, state in the New England region of the United States, bordered by New Hampshire to the west; the Gulf of Maine to the southeast; and the Provinces and territories of Canada, Canadian provinces of New Brunswick and Qu ...

Maine
, US and in
Minas Gerais Minas Gerais () is a state in Southeastern Brazil. It ranks as the second most populous, the third by Gross Domestic Product, gross domestic product (GDP), and the fourth largest by area in the country. The state's capital and largest city, Belo ...

Minas Gerais
,
Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At 8.5 million square kilometers (3.2 million square miles) and with over 211 mill ...

Brazil
.


Smoky quartz

Smoky quartz Smoky quartz is a brownish grey, translucent variety of quartz Quartz is a hard, crystalline A crystal or crystalline solid is a solid Solid is one of the four fundamental states of matter (the others being liquid, gas and ...

Smoky quartz
is a gray, translucent version of quartz. It ranges in clarity from almost complete transparency to a brownish-gray crystal that is almost opaque. Some can also be black. The translucency results from natural irradiation acting on minute traces of aluminum in the crystal structure.


Prasiolite

Prasiolite, also known as ''vermarine'', is a variety of quartz that is green in color. Since 1950, almost all natural prasiolite has come from a small
Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At 8.5 million square kilometers (3.2 million square miles) and with over 211 mill ...

Brazil
ian mine, but it is also seen in
Lower Silesia Lower Silesia ( pl, Dolny Śląsk; cz, Dolní Slezsko; german: Niederschlesien; hsb, Delnja Šleska; dsb, Dolna Šlazyńska; la, Silesia Inferior; Silesian German: ''Niederschläsing''; szl, Dolny Ślůnsk) is the northwestern part of the hi ...
in
Poland Poland, officially the Republic of Poland, is a country located in Central Europe. It is divided into 16 Voivodeships of Poland, administrative provinces, covering an area of , and has a largely Temperate climate, temperate seasonal cli ...

Poland
. Naturally occurring prasiolite is also found in the
Thunder Bay Thunder Bay is a city in and the seat of Thunder Bay District Thunder Bay District is a district and Census divisions of Canada, census division in Northwestern Ontario in the Canadian province of Ontario. The County seat, district seat is T ...

Thunder Bay
area of
Canada Canada is a country in the northern part of North America North America is a continent A continent is any of several large landmasses. Generally identified by convention (norm), convention rather than any strict criteria, ...

Canada
. It is a rare mineral in nature; most green quartz is heat-treated amethyst. File:Quartz-167895.jpg, Herkimer diamond File:Pure Quartz at Senckenberg Natural History Museum.jpg, Rock crystal File:Ametrin from Bolivia.jpg, Ametrine File:(61-365) Can you imagine? (5320329773).jpg, Amethyst File:Quartz-Magnesioriebeckite-118652.jpg, Blue quartz File:Quartz-46809.jpg, Chalcedony File:Citrine 1 (Russie).jpg, Citrine File:Quartz-159385.jpg, Rose quartz File:Quarzo, varietà prase, da avissalos, grecia.JPG, Prasiolite File:Quartz-159777.jpg, Rutilated quartz File:Quartz-154679.jpg, Sceptred quartz File:Quartz-168661.jpg, Smoky quartz


Synthetic and artificial treatments

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. Prasiolite, an olive colored material, is produced by heat treatment; natural prasiolite has also been observed in Lower Silesia in Poland. Although citrine occurs naturally, the majority is the result of heat-treating amethyst or smoky quartz.
Carnelian Carnelian (also spelled cornelian) is a brownish-red mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal stru ...

Carnelian
has been heat-treated to deepen its color since prehistoric times. Because natural quartz is often twinned, synthetic quartz is produced for use in industry. Large, flawless, single crystals are synthesized in an
autoclave An autoclave is a machine used to carry out industrial and scientific processes requiring elevated temperature and pressure in relation to ambient pressure/Ambient temperature, temperature. Autoclaves are used in medical applications to perform ...
via the hydrothermal process. Like other crystals, quartz may be coated with metal vapors to give it an attractive sheen.


Occurrence

Quartz is a defining constituent of
granite Granite () is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cool ...

granite
and other
felsic In geology Geology (from the Ancient Greek γῆ, ''gē'' ("earth") and -λoγία, ''-logia'', ("study of", "discourse")) is an Earth science concerned with the solid Earth, the rock (geology), rocks of which it is composed, and the processes ...
igneous rock Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main The three types of rocks, rock types, the others being Sedimentary rock, sedimentary and metamorphic rock, metamorphic. Igneous rock i ...
s. It is very common in
sedimentary rock Sedimentary rocks are types of rock Rock most often refers to: * Rock (geology) A rock is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its Chemical compoun ...

sedimentary rock
s such as
sandstone Sandstone is a clastic sedimentary rock of a clast (sand grain), derived from a basalt Basalt (, ) is a fine-grained extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron ('' mafic ' ...

sandstone
and
shale Shale is a fine-grained, clastic Clastic rocks are composed of fragments, or clasts, of pre-existing minerals In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defi ...

shale
. It is a common constituent of
schist Schist ( ) is a medium-grained metamorphic rock , a type of metamorphic rock Metamorphic rocks arise from the transformation of existing rock (geology), rock to new types of rock, in a process called metamorphism upright=1.35, Schematic r ...

schist
,
gneiss Gneiss ( ) is a common and widely distributed type of metamorphic rock Metamorphic rocks arise from the transformation of existing rock Rock most often refers to: * Rock (geology) A rock is any naturally occurring solid mass or ag ...

gneiss
,
quartzite Quartzite is a hard, non-Foliation (geology), foliated metamorphic rock which was originally pure quartz sandstone.Essentials of Geology, 3rd Edition, Stephen Marshak, p 182 Sandstone is converted into quartzite through heating and pressure usu ...

quartzite
and other
metamorphic rock Metamorphic rocks arise from the transformation of existing rock Rock most often refers to: * Rock (geology) A rock is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the mineral ...

metamorphic rock
s. Quartz has the lowest potential for
weathering Weathering is the deterioration of Rock (geology), rocks, soils and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms. Weathering occurs ''in situ'' (on site, with little o ...
in the
Goldich dissolution series The Goldich dissolution series is a way of predicting the relative stability or weathering Weathering is the breaking down of rocks, soil Soil (often stylized as SOiL) is an American rock band that was formed in Chicago ...
and consequently it is very common as a residual mineral in stream sediments and residual
soil Soil is a mixture In chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, comp ...

soil
s. 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. While the majority of quartz crystallizes from molten
magma Magma () is the molten or semi-molten natural material from which all igneous rock Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main The three types of rocks, rock types, the others ...

magma
, quartz also chemically precipitates from hot
hydrothermal Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC ...
veins Veins are blood vessels The blood vessels are the components of the circulatory system The circulatory system, also called the cardiovascular system or the vascular system, is an organ system An organ system is a biological system A b ...
as
gangue In mining, gangue () is the commercially worthless material that surrounds, or is closely mixed with, a wanted mineral in an ore deposit. It is thus distinct from overburden, which is the waste rock or materials overlying an ore or mineral body t ...
, sometimes with
ore ore – psilomelane Psilomelane is a group name for hard black manganese oxides including hollandite and romanechite. Psilomelane consists of hydrous manganese Manganese is a chemical element Image:Simple Periodic Table Chart- ...

ore
minerals like gold, silver and copper. Large crystals of quartz are found in magmatic
pegmatite A pegmatite is an igneous rock showing a very coarse Texture (geology), texure, with large interlocking crystals usually greater in size than and sometimes greater than . Most pegmatites are composed of quartz, feldspar, and mica, having a si ...
s. Well-formed crystals may reach several meters in length and weigh hundreds of kilograms. Naturally occurring quartz crystals of extremely high purity, necessary for the crucibles and other equipment used for growing
silicon Silicon is a chemical element with the Symbol (chemistry), symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic lustre, and is a Tetravalence, tetravalent metalloid and semiconductor. It is a member ...
wafers A wafer is a crisp, often sweet, very thin, flat, light and dry cookie A cookie is a Baked goods, baked or cooked snack or Dessert, dessert that is typically small, flat and sweet. It usually contains flour, sugar, egg, and some type of Cook ...
in the
semiconductor A semiconductor material has an electrical conductivity Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric curre ...
industry, are expensive and rare. A major mining location for high purity quartz is the Spruce Pine Gem Mine in
Spruce Pine, North Carolina Spruce Pine is a town in Mitchell County, North Carolina North Carolina () is a state State may refer to: Arts, entertainment, and media Literature * ''State Magazine'', a monthly magazine published by the U.S. Department of State * The ...
,
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

United States
. Quartz may also be found in Caldoveiro Peak, in
Asturias Asturias (, ; ast, Asturies ), officially the Principality of Asturias ( es, Principado de Asturias; ast, Principáu d'Asturies; : ''Principao d'Asturias''), is an in northwest . It is coextensive with the of Asturias and contains some of ...

Asturias
,
Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = , national_anthem = , image_map = , map_caption = , image_map2 ...

Spain
. The largest documented single crystal of quartz was found near Itapore, Goiaz, Brazil; it measured approximately 6.1×1.5×1.5 m and weighed 39,916
kilogram The kilogram (also kilogramme) is the base unit of mass Mass is the quantity Quantity is a property that can exist as a multitude or magnitude, which illustrate discontinuity and continuity. Quantities can be compared in terms of " ...
s.


Mining

Quartz is extracted from open pit mines. Miners occasionally use explosives to expose deep pockets of quartz. More frequently,
bulldozer A bulldozer or dozer (also called a crawler) is a large, motorized machine A machine is any physical system with ordered structural and functional properties. It may represent human-made or naturally occurring device molecular machine ...

bulldozer
s and
backhoe A backhoe—also called rear actor or back actor—is a type of excavating equipment, or excavator, digger, consisting of a digging bucket on the end of a two-part articulated arm. It is typically mounted on the back of a tractor or loader (eq ...

backhoe
s 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. 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. The popularity of
crystal healing A crystal or crystalline solid is a solid material whose constituents (such as atom An atom is the smallest unit of ordinary matter In classical physics and general chemistry, matter is any substance that has mass and takes up sp ...
has increased the demand for natural quartz crystals, which are now often mined in
developing countries A developing country is a sovereign state with a less developed Industrial sector, industrial base and a low Human Development Index (HDI) relative to other countries. However, this definition is not universally agreed upon. There is also no ...

developing countries
using primitive mining methods, sometimes involving
child labor Child labour refers to the exploitation of children through any form of work that deprives children of their childhood, interferes with their ability to attend regular school, and is mentally, physically, socially and morally harmful. Such e ...

child labor
.


Related silica minerals

Tridymite Tridymite is a high-temperature polymorph of silica Silicon dioxide, also known as silica, is an oxide of rutile. Ti(IV) centers are grey; oxygen centers are red. Notice that oxygen forms three bonds to titanium and titanium forms six bonds t ...

Tridymite
and
cristobalite Cristobalite is a mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure ...

cristobalite
are high-temperature polymorphs of SiO2 that occur in high-silica
volcanic A volcano is a rupture in the crust of a planetary-mass object A planet is an astronomical body orbit In physics, an orbit is the gravitationally curved trajectory of an physical body, object, such as the trajectory of a planet ar ...

volcanic
rocks.
Coesite Coesite is a form ( polymorph) of silicon dioxide Silicon dioxide, also known as silica, is an oxide of rutile. Ti(IV) centers are grey; oxygen centers are red. Notice that oxygen forms three bonds to titanium and titanium forms six bonds to ...

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 Stishovite is an extremely hard, dense tetragonal form ( polymorph) of silicon dioxide Silicon dioxide, also known as silica, is an oxide of rutile. Ti(IV) centers are grey; oxygen centers are red. Notice that oxygen forms three bonds to titani ...

Stishovite
is a yet denser and higher-pressure polymorph of SiO2 found in some meteorite impact sites.
Lechatelierite Lechatelierite is silica glass, amorphous SiO2, non-crystalline mineraloid. Structure Lechatelierite is a mineraloid as it does not have a crystal structure. Although not a true mineral, it is often classified in the quartz mineral group. Formati ...
is an
amorphous In condensed matter physics Condensed matter physics is the field of that deals with the macroscopic and microscopic physical properties of , especially the and which arise from forces between s. More generally, the subject deals with " ...
silica
glass Glass is a non- crystalline, often transparency and translucency, transparent amorphous solid, that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by ...

glass
SiO2 which is formed by
lightning Lightning is a naturally occurring electrostatic discharge Electrostatic discharge (ESD) is the sudden flow of electricity Electricity is the set of physical phenomena associated with the presence and motion Image:Leaving Yongsan ...

lightning
strikes in quartz
sand Sand is a granular material composed of finely divided rock (geology), rock and mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer ...

sand
.


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. Crystalline silica of respirable size is a recognized human
carcinogen A carcinogen is any substance, radionuclide A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide A nuclide (or nucleide, from atomic nucleus, nucleus, also known as nuclear species) is a class of atoms characte ...
and may lead to other diseases of the lungs such as
silicosis Silicosis is a form of occupational lung disease caused by inhalation of crystalline silica dust. It is marked by inflammation and scarring in the form of nodular lesions in the upper lobes of the lungs. It is a type of pneumoconiosis. Silico ...

silicosis
and
pulmonary fibrosis Pulmonary fibrosis is a condition in which the lungs become scarred over time. Symptoms include shortness of breath, a dry cough, feeling tired, weight loss, and nail clubbing. Complications may include pulmonary hypertension, respiratory failure ...
.


History

The word "quartz" comes from the
German German(s) may refer to: Common uses * of or related to Germany * Germans, Germanic ethnic group, citizens of Germany or people of German ancestry * For citizens of Germany, see also German nationality law * German language The German la ...

German
, which is of Slavic origin (Czech miners called it ''křemen''). Other sources attribute the word's origin to the
Saxon The Saxons ( la, Saxones, german: Sachsen, ang, Seaxan, osx, Sahson, nds, Sassen, nl, Saksen) were a group of early Germanic Germanic may refer to: * Germanic peoples, an ethno-linguistic group identified by their use of the Germanic langua ...
word ''Querkluftertz'', meaning ''cross-vein ore''. Quartz is the most common material identified as the mystical substance
maban Maban or Mabain is a material that is held to be magic Magic may refer to: * Magic (supernatural) Magic is the application of beliefs, rituals or actions employed in the belief that they can subdue or manipulate natural or supernatural ...

maban
in
Australian Aboriginal mythology Australian Aboriginal religion and mythology is the sacred spirituality represented in the stories performed by Aboriginal Australians Aboriginal Australians are the various Indigenous peoples Indigenous peoples, also referred to ...
. It is found regularly in passage tomb cemeteries in Europe in a burial context, such as
Newgrange Newgrange ( ga, Sí an Bhrú) is a prehistoric Prehistory, also known as pre-literary history, is the period of human history Human history, also known as world history, is the description of humanity's past. It is informed by archa ...

Newgrange
or
Carrowmore Carrowmore ( ga, An Cheathrú Mhór, 'the great quarter') is a large group of megalithic monuments on the Cúil Irra peninsula near Sligo, Ireland. They were built in the 4th millennium BCE, during the Neolithic era. There are thirty surviving ...
in
Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic. It is separated from Great Britain to its east by the North Channel (Great Britain and Ireland), North Channel, the Irish Sea ...

Ireland
. The
Irish Irish most commonly refers to: * Someone or something of, from, or related to: ** Ireland, an island situated off the north-western coast of continental Europe ** Northern Ireland, a constituent unit of the United Kingdom of Great Britain and North ...
word for quartz is ''grianchloch'', which means 'sunstone'. Quartz was also used in
Prehistoric Ireland The prehistory of Ireland has been pieced together from archaeological evidence, which has grown at an increasing rate over the last decades. It begins with the first evidence of permanent human residence in Ireland Ireland (; ga, Éire ; ...
, as well as many other countries, for
stone tool A stone tool is, in the most general sense, any tool made either partially or entirely out of Rock (geology), stone. Although stone tool-dependent societies and cultures still exist today, most stone tools are associated with prehistory, prehisto ...

stone tool
s; both vein quartz and rock crystal were as part of the
lithic technology In archaeology Archaeology or archeology is the study of human activity through the recovery and analysis of material culture. Archaeology is often considered a branch of socio-cultural anthropology, but archaeologists also draw from biolo ...
of the prehistoric peoples. While
jade Jade is a mineral, much used in some cultures as jewellery and for ornaments, mostly known for its green varieties, though it appears naturally in other colors as well, notably yellow and white. Jade can refer to either of two different silica ...

jade
has been since earliest times the most prized semi-precious stone for carving in
East Asia East Asia is the eastern region of Asia, which is defined in both Geography, geographical and culture, ethno-cultural terms. The modern State (polity), states of East Asia include China, Japan, Mongolia, North Korea, South Korea, and Taiwan. ...

East Asia
and
Pre-Columbian In the history of the Americas, the pre-Columbian era spans from the original settlement of North and South America in the Upper Paleolithic The Upper Paleolithic (or Upper Palaeolithic) also called the is the third and last subdivision o ...
America, in Europe and the Middle East the different varieties of quartz were the most commonly used for the various types of
jewelry Jewellery or jewelry consists of decorative items worn for personal adornment 150px, The principal adornment of these girls from the Bundu tribe in Sierra Leone is the adornment of bodies and faces with markings produced by the smearing on by ...

jewelry
and
hardstone carving Hardstone carving is a general term in art history and archaeology Archaeology or archeology is the study of human activity through the recovery and analysis Analysis is the process of breaking a complexity, complex topic or Substance t ...
, including
engraved gem An engraved gem, frequently referred to as an intaglio, is a small and usually semi-precious A gemstone (also called a fine gem, jewel, precious stone, or semi-precious stone) is a piece of mineral In geology Geology (from the Ancien ...
s and cameo gems, rock crystal vases, and extravagant vessels. The tradition continued to produce objects that were very highly valued 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. Roman naturalist
Pliny the Elder #REDIRECT Pliny the Elder #REDIRECT Pliny the Elder#REDIRECT Pliny the Elder Gaius Plinius Secundus (AD 23/2479), called Pliny the Elder (), was a Roman author, a naturalist Natural history is a domain of inquiry involving organisms, includi ...

Pliny the Elder
believed quartz to be water
ice Ice is water Water (chemical formula H2O) is an , transparent, tasteless, odorless, and , which is the main constituent of 's and the s of all known living organisms (in which it acts as a ). It is vital for all known forms of , eve ...

ice
, permanently frozen after great lengths of time. (The word "crystal" comes from the Greek word ''κρύσταλλος'', "ice".) He supported this idea by saying that quartz is found near glaciers in the Alps, but not on volcanic mountains, and that large quartz crystals were fashioned into spheres to cool the hands. This idea persisted until at least the 17th century. He also knew of the ability of quartz to split light into a
spectrum A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum Continuum may refer to: * Continuum (measurement) Continuum theories or models expla ...

spectrum
. In the 17th century,
Nicolas Steno Nicolas Steno ( da, Niels Steensen; Latinized to ''Nicolaus Steno'' or ''Nicolaus Stenonius''; 1 January 1638 – 25 November 1686
Nicolas Steno
's study of quartz paved the way for modern
crystallography Crystallography is the experimental science of determining the arrangement of atoms in crystalline solids (see crystal structure). The word "crystallography" is derived from the Greek language, Greek words ''crystallon'' "cold drop, frozen drop" ...

crystallography
. He discovered that regardless of a quartz crystal's size or shape, its long prism faces always joined at a perfect 60° angle. Quartz's
piezoelectric Piezoelectricity (, ) is the electric charge Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. Electric charge can be ''positive'' or ''negative'' (commonly carrie ...

piezoelectric
properties were discovered by
Jacques Ancient and noble French family names, Jacq, Jacques, or James are believed to originate from the Middle Ages in the historic northwest Brittany region in France France (), officially the French Republic (french: link=no, République fran ...
and
Pierre Curie Pierre Curie ( , ; 15 May 1859 – 19 April 1906) was a French physicist, a pioneer in crystallography, magnetism, piezoelectricity, and radioactivity. In 1903, he received the Nobel Prize in Physics with his wife, Marie Curie (née Skłodow ...
in 1880. The
quartz oscillator A crystal oscillator is an electronic oscillator An electronic oscillator is an electronic circuit File:PExdcr01CJC.jpg, 200px, A circuit built on a printed circuit board (PCB). An electronic circuit is composed of individual electronic component ...

quartz oscillator
or resonator was first developed by
Walter Guyton Cady Walter Guyton Cady (December 10, 1874 – December 9, 1974) was a noted American physicist A physicist is a scientist A scientist is a person who conducts scientific research The scientific method is an Empirical evidence, empirical ...
in 1921. George Washington Pierce designed and patented in 1923. Warren Marrison created the first quartz oscillator clock based on the work of Cady and Pierce in 1927. Efforts to synthesize quartz began in the mid nineteenth 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 Karl Franz Emil von Schafhäutl (16 February 1803 in Ingolstadt Ingolstadt ( , , Austro-Bavarian language, Austro-Bavarian: ) is a city in Bavaria, Germany, on the banks of the Danube, in the centre of Bavaria. In 2016, it had 133,638 citizens, ma ...
(1803–1890) was the first person to synthesize quartz when in 1845 he created microscopic quartz crystals in a pressure cooker. However, the quality and size of the crystals that were produced by these early efforts were poor. 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 the 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. 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 Nokia Bell Labs (formerly named Bell Labs Innovations (1996–2007), AT&T Bell Laboratories (1984–1996) and Bell Telephone Laboratories (1925–1984)) is an American industrial research and scientific development company A company, abbrev ...
and with the
Brush Development Company Brush Development Company was a manufacturer of audio, phonographic products and magnetic recording technologies located in Cleveland, Ohio. It was absorbed into Clevite in 1952. History The business was founded in 1919 by Alfred L. Williams as B ...
of Cleveland, Ohio to synthesize crystals following Nacken's lead. (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 to date. By the 1950s,
hydrothermal synthesis crystal grown by the hydrothermal method Hydrothermal synthesis includes the various techniques of crystallizing substances from high-temperature aqueous solution An aqueous solution is a solution Image:SaltInWaterSolutionLiquid.jpg, Making ...
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. File:Milan Jug with cut festoon decoration.jpg, Rock crystal jug with cut festoon decoration by
Milan Milan (, , Milanese: ; it, Milano ) is a city in northern Italy, capital of Lombardy, and the List of cities in Italy, second-most populous city proper in Italy after Rome. The city proper has a population of about 1.4 million, while its ...

Milan
workshop from the second half of the 16th century,
National Museum A national museum is a museum maintained and funded by a national government. In many countries it denotes a museum run by the central government, while other museums are run by regional or local governments. In other countries a much greater numb ...
in
Warsaw Warsaw, * la, Varsovia (Polish language, Polish: ''Warszawa'' ), officially the Capital City of Warsaw, is the capital and List of cities and towns in Poland, largest city of Poland. The metropolis stands on the Vistula, River Vistula in e ...

Warsaw
. The city of Milan, apart from
Prague Prague ( ; cs, Praha ; german: Prag, ; la, Praga) is the capital and largest city A city is a large human settlement In geography, statistics and archaeology, a settlement, locality or populated place is a community in which people ...

Prague
and
Florence Florence ( ; it, Firenze ) is a city in Central-Northern Italy Italy ( it, Italia ), officially the Italian Republic ( it, Repubblica Italiana, links=no ), is a country consisting of Italian Peninsula, a peninsula delimited by the Al ...

Florence
, was the main
Renaissance The Renaissance ( , ) , from , with the same meanings. is a period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in ...

Renaissance
centre for crystal cutting. File:Prototype synthetic quartz autoclave 1959.jpg, Synthetic quartz crystals produced in the autoclave shown in
Western Electric The Western Electric Company was an American electrical engineering Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics ...
's pilot hydrothermal quartz plant in 1959 File:Ewer birds Louvre MR333.jpg,
Fatimid The Fatimid Caliphate ( ar, ٱلْخِلَافَة ٱلْفَاطِمِيَّة , al-Ḫilāfa al-Fāṭimiyya) was an Ismaili Shia Ismāʿīlism ( ar, الإسماعيلية, ''al-ʾIsmāʿīlīyah''; fa, اسماعیلیان, ''E ...

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


Piezoelectricity

Quartz crystals have
piezoelectric Piezoelectricity (, ) is the electric charge Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. Electric charge can be ''positive'' or ''negative'' (commonly carrie ...

piezoelectric
properties; they develop an
electric potential The electric potential (also called the ''electric field potential'', potential drop, the electrostatic potential) is defined as the amount of work Work may refer to: * Work (human activity), intentional activity people perform to support the ...

electric potential
upon the application of
mechanical stress In continuum mechanics, stress is a physical quantity that expresses the internal forces that neighbouring particles of a continuous material exert on each other, while deformation (mechanics)#Strain, strain is the measure of the deformation of ...
. An early use of this property of quartz crystals was in
phonograph A phonograph, in its later forms also called a gramophone (as a trademark since 1887, as a generic name in the UK since 1910) or since the 1940s called a record player, is a device for the mechanical and analogue recording and reproduction ...

phonograph
pickups. One of the most common piezoelectric uses of quartz today is as a
crystal oscillator A crystal oscillator is an electronic oscillator An electronic oscillator is an electronic circuit 200px, A circuit built on a printed circuit board (PCB). An electronic circuit is composed of individual electronic component An electroni ...

crystal oscillator
. The
quartz clock Quartz clocks and quartz watches are timepieces that use an electronic oscillator An electronic oscillator is an electronic circuit 200px, A circuit built on a printed circuit board (PCB). An electronic circuit is composed of individual el ...

quartz clock
is a familiar device using the mineral. 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 microbalanceA quartz crystal microbalance (QCM) (also known as ''quartz microbalance'' (QMB), sometimes also as ''quartz crystal nanobalance'' (QCN)) measures a mass variation per unit area by measuring the change in frequency Frequency is the number of occ ...
and in thin-film thickness monitors. (NB. This was partially presented at Physikertagung in Heidelberg in October 1957.)


See also

*
Fused quartz Fused quartz, fused silica or quartz glass is a glass Glass is a non- crystalline, often transparency and translucency, transparent amorphous solid, that has widespread practical, technological, and decorative use in, for example, window pa ...
*
List of minerals This is a list of minerals for which there are articles on Wikipedia. Mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specif ...
* *
Quartz reef mining Quartz reef mining is a type of gold mining in "reefs" (Vein (geology), veins) of quartz. Quartz is one of the most common minerals in the earth's crust, and most quartz veins do not carry gold, but those that have gold are avidly hunted by prospect ...
*
Quartzolite Quartzolite or silexite is an intrusive igneous rock Igneous rock (derived from the Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken ...
*
Shocked quartz Shocked quartz is a form of quartz that has a microscopic structure that is different from normal quartz. Under intense pressure (but limited temperature), the crystalline structure of quartz is deformed along planes inside the crystal. These pla ...


References


External links


Quartz varieties, properties, crystal morphology. Photos and illustrations


* * ttps://web.archive.org/web/20071012101816/http://www.connogue.com/quartslab/html/terminology.html Terminology used to describe the characteristics of quartz crystals when used as oscillators
Quartz use as prehistoric stone tool raw material
{{Authority control Quartz, Dielectrics Piezoelectric materials Symbols of Georgia (U.S. state) Trigonal minerals Minerals in space group 152 or 154 Minerals in space group 180 or 181 Luminescent minerals Quartz gemstones, Quartz gemstones Industrial minerals Silica polymorphs Symbols of South Dakota