Quartz
Quartz crystal group from Arkansas
General
Category	Mineral
Chemical formula	Silica (silicon dioxide, SiO2)
Identification
Color	Clear (if no impurities); also see Varieties
Crystal habit	6-sided prism ending in 6-sided pyramid (typical)
Crystal system	rhombohedral class 32
Twinning	Dauphine law, Brazil law and Japan law
Cleavage	None
Fracture	Conchoidal
Mohs Scale hardness	7 - lower in impure varieties
Luster	Vitreous/glossy
Refractive index	nω = 1. Arkansas ( is a state located in the southern region of the United States. A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes The Chemical compound silicon dioxide, also known as silica or silox (from the Latin " Silex " is an Oxide In Mineralogy, shape and size give rise to descriptive terms applied to the typical appearance or habit of Crystals The many terms used by mineralogists A crystal system is a category of Space groups which characterize Symmetry of structures in three dimensions with Translational symmetry in three directions In Crystallography, the rhombohedral (or trigonal) Crystal system is one of the seven lattice point groups named after the two-dimensional Crystal twinning occurs when two separate crystals share some of the same Crystal lattice points in a symmetrical manner Cleavage, in Mineralogy, is the tendency of crystalline materials to split along definite planes creating smooth surfaces of which there are several named types In the field of Mineralogy, fracture is a term used to describe the shape and texture of the surface formed when a Mineral is broken The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material Lustre (or luster) is a description of the way light interacts with the surface of a Crystal, rock, or Mineral. The refractive index (or index of Refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves is reduced inside the medium 543 - 1. 545 nε = 1. 552 - 1. 554
Optical Properties	Uniaxial (+)
Birefringence	+0. Birefringence, or double refraction, is the decomposition of a ray of Light into two rays (the ordinary ray and the extraordinary ray 009 (B-G interval)
Pleochroism	None
Streak	White
Specific gravity	2. Pleochroism is an Optical phenomenon in which grains of a rock appear to be different colors when observed at different angles under a Petrographic microscope. The streak (also called powder color) of a Mineral is the Color of the powder produced when it is dragged across an unweathered surface Specific gravity is defined as the ratio of the Density of a given solid or liquid substance to the density of water at a specific temperature and pressure typically 65 constant; variable in impure varieties
Melting point	1650 (±75) °C
Solubility	11. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. 0 +/- 1. 1 PPM @ 25 C
Diaphaneity	Transparent to translucent
Other Characteristics	Piezoelectric

Quartz (from German Quarz (help·info)^[1]) is the most abundant mineral in the Earth's continental crust (although feldspar is more common in the world as a whole). The German language (de ''Deutsch'') is a West Germanic language and one of the world's major languages. A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 The continental crust is the layer of granitic, Sedimentary, and Metamorphic rocks which form the Continents and the areas of shallow seabed Feldspar is the name of a group of rock-forming Minerals which make up as much as 60% of the Earth 's crust. It is made up of a lattice of silica (SiO₂) tetrahedra. In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. The Chemical compound silicon dioxide, also known as silica or silox (from the Latin " Silex " is an Oxide Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the A tetrahedron (plural tetrahedra) is a Polyhedron composed of four triangular faces three of which meet at each vertex. Quartz has a hardness of 7 on the Mohs scale and a density of 2. The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 65 g/cm³.

Crystal habit

Quartz belongs to the rhombohedral crystal system. In Crystallography, the rhombohedral (or trigonal) Crystal system is one of the seven lattice point groups named after the two-dimensional The ideal crystal shape is a six-sided prism terminating with six-sided pyramids at each end. In Mineralogy, shape and size give rise to descriptive terms applied to the typical appearance or habit of Crystals The many terms used by mineralogists General right and uniform prisms A right prism is a prism in which the joining edges and faces are perpendicular to the base faces A pyramid is a Building where the upper surfaces are triangular and converge on one point In nature quartz crystals are often twinned, 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. Crystal twinning occurs when two separate crystals share some of the same Crystal lattice points in a symmetrical manner Well-formed crystals typically form in a 'bed' that has unconstrained growth into a void, but because the crystals must be attached at the other end to a matrix, only one termination pyramid is present. A quartz geode is such a situation where the void is approximately spherical in shape, lined with a bed of crystals pointing inward. Geodes ( Greek geoides, "earthlike" are geological rock formations which occur in sedimentary and certain Volcanic

Varieties

Pure quartz is colorless or white, colored varieties include rose quartz, amethyst, smoky quartz, milky quartz, and others. Amethyst is a violet variety of Quartz often used as an Ornamental stone in Jewelry. Quartz goes by an array of different names. The most important distinction between types of quartz is that of macrocrystalline (individual crystals visible to the unaided eye) and the microcrystalline or cryptocrystalline varieties (aggregates of crystals visible only under high magnification). A microcrystalline material is a crystallized substance or rock which contains small Crystals that are visible only through microscopic examination Cryptocrystalline is a rock texture which is so finely crystalline being made up of such minute Crystals that its crystalline nature is only vaguely revealed Chalcedony is a generic term for cryptocrystalline quartz. Chalcedony is a Cryptocrystalline form of Silica, composed of very fine intergrowths of the minerals Quartz and Moganite. The cryptocrystalline varieties are either translucent or mostly opaque, while the transparent varieties tend to be macrocrystalline.

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. This does not always hold true.

Rose quartz

Milk quartz

Rutilated quartz crystal

Synthetic and artificial treatments

A synthetic quartz crystal grown by the hydrothermal method, about 19 cm long and weights about 127 grams

Not all varieties of quartz are naturally occurring. Amethyst is a violet variety of Quartz often used as an Ornamental stone in Jewelry. For the politician of this name see Walter McLennan Citrine 1st Baron Citrine, for the GFP protein derivative see Yellow fluorescent protein. Prasiolite, green-quartz or vermarine is a green form of Quartz. Rose quartz is a type of Quartz which exhibits a pale pink to rose red hue In Gemmology, an asterism is an Optical phenomenon displayed by some rubies, Sapphires and other gems (i Rutile is a Mineral composed primarily of Titanium dioxide, Ti[[oxygen O]]2 Milk quartz or milky quartz may be the most common variety of crystalline Quartz and can be found almost anywhere This article is about the mineral variety for the English term for the Helmet worn in the 16th century see Morion (helmet. Carnelian, sometimes spelled cornelian, is a red or reddish-brown variant of Chalcedony. Hydrothermal synthesis includes the various techniques of crystallizing substances from high-temperature Aqueous solutions at high Vapor pressures also termed "hydrothermal Prasiolite, an olive colored material, is produced by heat treatment; natural prasiolite has also been observed in Lower Silesia in Poland. Prasiolite, green-quartz or vermarine is a green form of Quartz. Although citrine occurs naturally, the majority is the result of heat-treated amethyst. For the politician of this name see Walter McLennan Citrine 1st Baron Citrine, for the GFP protein derivative see Yellow fluorescent protein. Carnelian is widely heat-treated to deepen its color. Carnelian, sometimes spelled cornelian, is a red or reddish-brown variant of Chalcedony.

Due to natural quartz being so often twinned, much of the quartz used in industry is synthesized. Crystal twinning occurs when two separate crystals share some of the same Crystal lattice points in a symmetrical manner Large, flawless and untwinned crystals are produced in an autoclave via the hydrothermal process; emeralds are also synthesized in this fashion. An autoclave is a pressurized device designed to heat aqueous solutions above their Boiling point at normal atmospheric pressure to achieve sterilization Hydrothermal synthesis includes the various techniques of crystallizing substances from high-temperature Aqueous solutions at high Vapor pressures also termed "hydrothermal Emeralds are a variety of the Mineral Beryl (Be3Al2(SiO36 colored Green by trace amounts While these are still commonly referred to as quartz, the correct term for this material is silicon dioxide. The Chemical compound silicon dioxide, also known as silica or silox (from the Latin " Silex " is an Oxide

Occurrence

Quartz occurs in hydrothermal veins and pegmatites. Hydrothermal circulation in its most general sense is the circulation of hot water 'hydros' in the Greek meaning water and 'thermos' meaning heat In Geology, a vein is a finite volume within a rock, having a distinct shape filled with Crystals of one or more Minerals which were precipitated Pegmatite is a very coarse-grained Igneous rock that has a grain size of 20 mm or more such rocks are referred to as pegmatitic. Well-formed crystals may reach several meters in length and weigh hundreds of kilograms. Mass is a fundamental concept in Physics, roughly corresponding to the Intuitive idea of how much Matter there is in an object These veins may bear precious metals such as gold or silver, and form the quartz ores sought in mining. Precious Metal is the eighteenth episode in the of the popular American Crime drama, which is set in Las Vegas, Nevada. Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 Silver (ˈsɪlvɚ is a Chemical element with the symbol " Ag " (argentum from the Ancient Greek: ἀργήντος - argēntos gen Mining is the extraction of valuable Minerals or other geological materials from the earth usually (but not always from an Ore body Erosion of pegmatites may reveal expansive pockets of crystals, known as "cathedrals. "

Quartz is a common constituent of granite, sandstone, limestone, and many other igneous, sedimentary, and metamorphic rocks. Granite (ˈɡrænɪt is a common and widely occurring type of intrusive, Felsic, igneous rock. Sandstone is a Sedimentary rock composed mainly of Sand -size Mineral or rock grains. Limestone is a Sedimentary rock composed largely of the Mineral Calcite ( Calcium carbonate: CaCO3 Igneous rocks (etymology from Latin ignis, fire are rocks formed by solidification of cooled Magma (molten rock Sedimentary rock is one of the three main rock types (the others being igneous and Metamorphic rock) Metamorphic rock is the result of the transformation of an existing rock type the protolith, in a process called Metamorphism, which means "change

Related silica minerals

Tridymite and cristobalite are high-temperature polymorphs of SiO₂ that occur in high-silica volcanic rocks. Tridymite is a high-temperature polymorph of Quartz and usually occurs as minute tabular white or colorless pseudo-hexagonal Triclinic crystals or scales The mineral cristobalite is a high-temperature polymorph of Quartz and Tridymite. Polymorphism in Materials science is the ability of a solid material to exist in more than one form or Crystal structure Plate tectonics and hotspots Divergent plate boundaries At the Coesite is a denser polymorph of quartz found in some meteorite impact sites and in metamorphic rocks formed at pressures greater than those typical of the Earth's crust. Coesite is a form ( polymorph) of Silicon dioxide Si[[oxygen O]]2 that is formed when very high pressure (2&ndash3 Gigapascals and Stishovite is a yet denser and higher-pressure polymorph of quartz found in some meteorite impact sites. Stishovite (after SM Stishov 20th-century Russian mineralogist is an extremely hard dense Tetragonal form ( polymorph) of Silicon dioxide. Lechatelierite is an amorphous silica glass SiO₂ which is formed by lightning strikes in quartz sand. Lechatelierite is Silica glass Amorphous SiO2 One common way in which lechatelierite forms naturally is by very high temperature melting of Quartz An amorphous solid is a Solid in which there is no Long-range order of the positions of the Atoms (Solids in which there is long-range atomic order are Glass in the common sense refers to a Hard, Brittle, transparent Solid, such as that used for Windows many Lightning is an atmospheric discharge of Electricity, which typically occurs during Thunderstorms and sometimes during volcanic eruptions or Sand is a naturally occurring Granular material composed of finely divided rock and Mineral particles

History

Quartz crystal showing transparency. In Optics, transparency (also called pellucidity) is the Material property of allowing

The name "quartz" comes from the German "Quarz", which is of Slavic origin (Czech miners called it křemen). Other sources insist the name is from the Saxon word "Querkluftertz", meaning cross-vein ore. Upper Saxon ( German: Obersächsisch or colloquially (but incorrectly Sächsisch) is a Central German Dialect spoken ^[2]

Quartz is the most common material identified as the mystical substance maban in Australian Aboriginal mythology. Maban or Mabain is a material that is held to be magical in Australian Aboriginal mythology. Australian Aboriginal myths (also known as Dreamtime stories Songlines or Aboriginal Oral literature) are the stories traditionally performed It is found regularly in passage tomb cemeteries in Europe in a burial context, eg. Newgrange or Carrowmore in the Republic of Ireland. Newgrange (Dún Fhearghusa is one of the Passage tombs of the Brú na Bóinne complex in County Meath, one of the most famous Carrowmore (Ceathrú Mór meaning Great Quarter is the site of a prehistoric Ritual landscape on the Knocknarea or Cúil Irra Peninsula in County Ireland ( Irish: Éire, ˈeːrʲə is a country in north-western Europe. The Irish word for quartz is grian cloch, which means 'stone of the sun'. Irish (ga ''Gaeilge'' is a Goidelic language of the Indo-European language family originating in Ireland and historically spoken by the Irish.

Roman naturalist Pliny the Elder believed quartz to be water ice, permanently frozen after great lengths of time. Gaius or Caius Plinius Secundus, ( AD 23 – August 25, AD 79 better known as Pliny the Elder, was an ancient Author Ice is a Solid phase, usually crystalline, of a Non-metalic substance that is liquid or gas at Room temperature, such as Ammonia (The word "crystal" comes from the Greek word for 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. 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 infinitely within a continuum. This idea persisted until at least the 1600s.

Nicolas Steno's study of quartz paved the way for modern crystallography. Nicolas Steno ( Danish: Niels Stensen; Latinized to Nicolaus Stenonis) ( January 10, 1638 - November 25, Crystallography is the experimental science of determining the arrangement of Atoms in Solids In older usage it is the scientific study of Crystals The He discovered that no matter how distorted a quartz crystal, the long prism faces always made a perfect 60 degree angle.

Charles Sawyer invented the commercial quartz crystal manufacturing process in Cleveland, Ohio, United States. Cleveland is a City in the US state of Ohio and the County seat of Cuyahoga County, the most populous county in the state Ohio ( is a Midwestern state of the United States. As part of the Great Lakes region, Ohio has long been a cultural and geographical crossroads The United States of America —commonly referred to as the This initiated the transition from mined and cut quartz for electrical appliances to manufactured quartz.

Quartz's piezoelectric properties were discovered by Jacques and Pierre Curie in 1880. Piezoelectricity is the ability of some materials (notably Crystals and certain Ceramics including bone to generate an Electric potential in response to Paul-Jacques Curie ( October 29, 1856 &ndash 1941 was a French Physicist and professor at the University of Montpellier. Pierre Curie (15 May 1859 &ndash 19 April 1906 was a French physicist, a pioneer in Crystallography, Magnetism, Piezoelectricity The quartz oscillator or resonator was first developed by Walter Guyton Cady in 1921 [1]. A crystal oscillator is an Electronic circuit that uses the mechanical Resonance of a vibrating Crystal of piezoelectric material to create an Dr Walter Guyton Cady ( December 10, 1874 – December 9, 1974) was a noted American physicist and Electrical engineer. George Washington Pierce designed and patented quartz crystal oscillators in 1923 [2]. Warren Marrison created the first quartz oscillator clock based on the work of Cady and Pierce in 1927 [3].

Quartz crystals are rotary polar (see rotary polarization) and have the ability to rotate the plane of polarization of light passing through them. Rotary polarization is an optical phenomenon occurring in certain crystalline materials They are also highly piezoelectric, becoming polarized with a negative charge on one end and a positive charge on the other when subjected to pressure. They will vibrate if an alternating electric current is applied to them. This proves them to be highly important in commerce for making pressure gauges, oscillators, resonators and watches.

Piezoelectricity

Quartz crystals have piezoelectric properties, that is they develop an electric potential upon the application of mechanical stress. Piezoelectricity is the ability of some materials (notably Crystals and certain Ceramics including bone to generate an Electric potential in response to An early use of this property of quartz crystals was in phonograph pickups. The phonograph, or gramophone, was the most common device for playing recorded Sound from the 1870s through the 1980s One of the most common piezoelectric uses of quartz today is as a crystal oscillator. A crystal oscillator is an Electronic circuit that uses the mechanical Resonance of a vibrating Crystal of piezoelectric material to create an The quartz clock is a familiar device using the mineral. A quartz clock is a Clock that uses an Electronic oscillator that is regulated by a Quartz crystal to keep time 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. A quartz crystal microbalance (QCM measures a mass per unit area by measuring the change in Frequency of a Quartz crystal resonator Thin-film thickness monitors, deposition rate controllers, and so on are a family of instruments used in high and ultra-high Vacuum systems

See also

• Aqua aura
• Azeztulite
• Flame aura
• Fused quartz
• List of minerals
• Shocked quartz
• Quartz reef mining

References

• Hurlbut, Cornelius S. Aqua aura is a term used to describe a natural Crystal that has been coated with gold fumes Flame Aura or Rainbow Aura Quartz have been enhanced with a combination of Titanium and Niobium. Fused quartz and fused silica are types of Glass containing primarily Silica in amorphous (non- Crystalline form This is a List of Minerals for which there are Wikipedia articles Shocked quartz is a form of Quartz that has a microscopic structure that is different from normal quartz Primary Gold typically occurs in Quartz veins. The extraction of gold Ore from these hard quartz veins was historically referred to as quartz reef ; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed. , ISBN 0-471-80580-7
• Quartz varieties, properties, crystal morphology. Photos and illustrations
• Arkansas quartz, Rockhounding Arkansas
• Gilbert Hart Nomenclature of Silica, American Mineralogist, Volume 12, pages 383-395, 1927
• Mindat.org
• Queensland University of Technology Origin of the word quartz.
• PDF of Charles Sawyer's cultured quartz process description
• Smithsonian Institute, Inventors of quartz oscillating devices
• http://www.webmineral.com/data/Quartz.shtml
• http://www.gemstone.org/gem-by-gem/english/quartz.html
• http://mineral.galleries.com/minerals/silicate/quartz/quartz.htm
• http://mineral.galleries.com/minerals/gemstone/rock_cry/rock_cry.htm
• Terminology used to describe the characteristics of Quartz Crystals when used as oscillators
• http://www.realgems.org/list_of_gemstones/quartz.html RealGems. org Quartz