Portal:Minerales

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El portal de minerales

En geología y mineralogía , un mineral o especie mineral es, en términos generales, una sustancia sólida con una composición química bastante bien definida y una estructura cristalina específica que se presenta de forma natural en forma pura.

La definición geológica de mineral excluye normalmente los compuestos que se encuentran únicamente en los organismos vivos. Sin embargo, algunos minerales suelen ser compuestos biogénicos (como la calcita ) o orgánicos en el sentido químico (como la melita ). Además, los organismos vivos suelen sintetizar minerales inorgánicos (como la hidroxiapatita ) que también se encuentran en las rocas.

El concepto de mineral es distinto al de roca , que es cualquier material geológico sólido y relativamente homogéneo a una escala suficientemente grande. Una roca puede estar formada por un tipo de mineral o puede ser un agregado de dos o más tipos diferentes de minerales, separados espacialmente en fases distintas .

Algunas sustancias sólidas naturales sin una estructura cristalina definida, como el ópalo o la obsidiana , se denominan más propiamente mineraloides . Si un compuesto químico se presenta de forma natural con diferentes estructuras cristalinas, cada estructura se considera una especie mineral diferente. Así, por ejemplo, el cuarzo y la stishovita son dos minerales diferentes que consisten en el mismo compuesto, el dióxido de silicio . ( Artículo completo... )

La mineralogía es una disciplina de la geología que se especializa en el estudio científico de la química , la estructura cristalina ylas propiedades físicas (incluidas las ópticas ) de los minerales y los artefactos mineralizados. Los estudios específicos dentro de la mineralogía incluyen los procesos de origen y formación de los minerales, la clasificación de los minerales, su distribución geográfica y su utilización. ( Artículo completo... )

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Artículos seleccionados

Image 1

El corindón es unaforma cristalina de óxido de aluminio _(Al2O3 ) que _normalmente contiene trazas de hierro , titanio , vanadio y cromo . Es un mineral formador de rocas . Es un material naturalmente transparente , pero puede tener diferentes colores dependiendo de la presencia de impurezas de metales de transición en su estructura cristalina. El corindón tiene dos variedades de gemas principales: rubí y zafiro . Los rubíes son rojos debido a la presencia de cromo, y los zafiros exhiben una gama de colores dependiendo del metal de transición que esté presente. Un tipo raro de zafiro, el zafiro padparadscha , es de color rosa anaranjado.El nombre "corindón" se deriva de lapalabra tamil - dravídica kurundam (rubí-zafiro) (que aparece en sánscrito como kuruvinda ).Debido a la dureza del corindón (se define que el corindón puro tiene 9,0 en la escala de Mohs ), puede rayar casi todos los demás minerales. Se utiliza comúnmente como abrasivo en papel de lija y en herramientas grandes que se utilizan para mecanizar metales, plásticos y madera. El esmeril , una variedad de corindón sin valor como piedra preciosa, se utiliza comúnmente como abrasivo. Es una forma granular negra de corindón, en la que el mineral está íntimamente mezclado con magnetita , hematita o hercinita .Además de su dureza, el corindón tiene una densidad de 4,02 g/cm³ (251 lb/cu ft), que es inusualmente alta para un mineral transparente compuesto por loselementos de baja masa atómica aluminio y oxígeno . ( Artículo completo... )
Image 2
Green fluorite with prominent cleavage

Cleavage, in mineralogy and materials science, is the tendency of crystalline materials to split along definite crystallographic structural planes. These planes of relative weakness are a result of the regular locations of atoms and ions in the crystal, which create smooth repeating surfaces that are visible both in the microscope and to the naked eye. If bonds in certain directions are weaker than others, the crystal will tend to split along the weakly bonded planes. These flat breaks are termed "cleavage". The classic example of cleavage is mica, which cleaves in a single direction along the basal pinacoid, making the layers seem like pages in a book. In fact, mineralogists often refer to "books of mica".

Diamond and graphite provide examples of cleavage. Each is composed solely of a single element, carbon. In diamond, each carbon atom is bonded to four others in a tetrahedral pattern with short covalent bonds. The planes of weakness (cleavage planes) in a diamond are in four directions, following the faces of the octahedron. In graphite, carbon atoms are contained in layers in a hexagonal pattern where the covalent bonds are shorter (and thus even stronger) than those of diamond. However, each layer is connected to the other with a longer and much weaker van der Waals bond. This gives graphite a single direction of cleavage, parallel to the basal pinacoid. So weak is this bond that it is broken with little force, giving graphite a slippery feel as layers shear apart. As a result, graphite makes an excellent dry lubricant.

While all single crystals will show some tendency to split along atomic planes in their crystal structure, if the differences between one direction or another are not large enough, the mineral will not display cleavage. Corundum, for example, displays no cleavage. (Full article...)
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The 423-carat (85 g) blue Logan Sapphire

Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide (α-Al₂O₃) with trace amounts of elements such as iron, titanium, cobalt, lead, chromium, vanadium, magnesium, boron, and silicon. The name sapphire is derived from the Latin word sapphirus, itself from the Greek word sappheiros (σάπφειρος), which referred to lapis lazuli. It is typically blue, but natural "fancy" sapphires also occur in yellow, purple, orange, and green colors; "parti sapphires" show two or more colors. Red corundum stones also occur, but are called rubies rather than sapphires. Pink-colored corundum may be classified either as ruby or sapphire depending on the locale. Commonly, natural sapphires are cut and polished into gemstones and worn in jewelry. They also may be created synthetically in laboratories for industrial or decorative purposes in large crystal boules. Because of the remarkable hardness of sapphires – 9 on the Mohs scale (the third-hardest mineral, after diamond at 10 and moissanite at 9.5) – sapphires are also used in some non-ornamental applications, such as infrared optical components, high-durability windows, wristwatch crystals and movement bearings, and very thin electronic wafers, which are used as the insulating substrates of special-purpose solid-state electronics such as integrated circuits and GaN-based blue LEDs. Sapphire is the birthstone for September and the gem of the 45th anniversary. A sapphire jubilee occurs after 65 years. (Full article...)
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Borax (also referred to as sodium borate, tincal (/ˈtɪŋkəl/) and tincar (/ˈtɪŋkər/)) is a salt (ionic compound), a hydrated or anhydrous borate of sodium, with the chemical formula Na₂H₂₀B₄O₁₇.

It is a colorless crystalline solid that dissolves in water to make a basic solution.

It is commonly available in powder or granular form and has many industrial and household uses, including as a pesticide, as a metal soldering flux, as a component of glass, enamel, and pottery glazes, for tanning of skins and hides, for artificial aging of wood, as a preservative against wood fungus, and as a pharmaceutic alkalizer. In chemical laboratories, it is used as a buffering agent.

The terms tincal and tincar refer to native borax, historically mined from dry lake beds in various parts of Asia. (Full article...)
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A rich seam of iridescent opal encased in matrix

Opal is a hydrated amorphous form of silica (SiO₂·nH₂O); its water content may range from 3% to 21% by weight, but is usually between 6% and 10%. Due to the amorphous chemical structure, it is classified as a mineraloid, unlike crystalline forms of silica, which are considered minerals. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most commonly found with limonite, sandstone, rhyolite, marl, and basalt.

The name opal is believed to be derived from the Sanskrit word upala (उपल), which means 'jewel', and later the Greek derivative opállios (ὀπάλλιος).

There are two broad classes of opal: precious and common. Precious opal displays play-of-color (iridescence); common opal does not. Play-of-color is defined as "a pseudo chromatic optical effect resulting in flashes of colored light from certain minerals, as they are turned in white light." The internal structure of precious opal causes it to diffract light, resulting in play-of-color. Depending on the conditions in which it formed, opal may be transparent, translucent, or opaque, and the background color may be white, black, or nearly any color of the visual spectrum. Black opal is considered the rarest, while white, gray, and green opals are the most common. (Full article...)
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Galena with minor pyrite

Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver.

Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms. It is often associated with the minerals sphalerite, calcite and fluorite. (Full article...)
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Talc, or talcum, is a clay mineral composed of hydrated magnesium silicate, with the chemical formula Mg₃Si₄O₁₀(OH)₂. Talc in powdered form, often combined with corn starch, is used as baby powder. This mineral is used as a thickening agent and lubricant. It is an ingredient in ceramics, paints, and roofing material. It is a main ingredient in many cosmetics. It occurs as foliated to fibrous masses, and in an exceptionally rare crystal form. It has a perfect basal cleavage and an uneven flat fracture, and it is foliated with a two-dimensional platy form.

The Mohs scale of mineral hardness, based on scratch hardness comparison, defines value 1 as the hardness of talc, the softest mineral. When scraped on a streak plate, talc produces a white streak, though this indicator is of little importance, because most silicate minerals produce a white streak. Talc is translucent to opaque, with colors ranging from whitish grey to green with a vitreous and pearly luster. Talc is not soluble in water, and is slightly soluble in dilute mineral acids.

Soapstone is a metamorphic rock composed predominantly of talc. (Full article...)
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Fibrous tremolite asbestos on muscovite

Asbestos (/æsˈbɛstəs, æz-, -tɒs/ ass-BES-təs, az-, -⁠toss) is a group of naturally occurring, toxic, carcinogenic and fibrous silicate minerals. There are six types, all of which are composed of long and thin fibrous crystals, each fibre (particulate with length substantially greater than width) being composed of many microscopic "fibrils" that can be released into the atmosphere by abrasion and other processes. Inhalation of asbestos fibres can lead to various dangerous lung conditions, including mesothelioma, asbestosis, and lung cancer. As a result of these health effects, asbestos is considered a serious health and safety hazard.

Archaeological studies have found evidence of asbestos being used as far back as the Stone Age to strengthen ceramic pots, but large-scale mining began at the end of the 19th century when manufacturers and builders began using asbestos for its desirable physical properties. Asbestos is an excellent thermal and electrical insulator, and is highly fire resistant, so for much of the 20th century, it was very commonly used around the world as a building material (particularly for its fire-retardant properties), until its adverse effects on human health were more widely recognized and acknowledged in the 1970s. Many buildings constructed before the 1980s contain asbestos.

The use of asbestos for construction and fireproofing has been made illegal in many countries. Despite this, around 255,000 people are thought to die each year from diseases related to asbestos exposure. In part, this is because many older buildings still contain asbestos; in addition, the consequences of exposure can take decades to arise. The latency period (from exposure until the diagnosis of negative health effects) is typically 20 years. The most common diseases associated with chronic asbestos exposure are asbestosis (scarring of the lungs due to asbestos inhalation) and mesothelioma (a type of cancer).

Many developing countries still support the use of asbestos as a building material, and mining of asbestos is ongoing, with the top producer, Russia, having an estimated production of 790,000 tonnes in 2020. (Full article...)
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Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula CuAl₆(PO4)₄(OH)₈·4H2O. It is rare and valuable in finer grades and has been prized as a gemstone for millennia due to its hue.

Like most other opaque gems, turquoise has been devalued by the introduction of treatments, imitations, and synthetics into the market. The robin egg blue or sky blue color of the Persian turquoise mined near the modern city of Nishapur, Iran, has been used as a guiding reference for evaluating turquoise quality. (Full article...)
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Rutile is an oxide mineral composed of titanium dioxide (TiO₂), the most common natural form of TiO₂. Rarer polymorphs of TiO₂ are known, including anatase, akaogiite, and brookite.

Rutile has one of the highest refractive indices at visible wavelengths of any known crystal and also exhibits a particularly large birefringence and high dispersion. Owing to these properties, it is useful for the manufacture of certain optical elements, especially polarization optics, for longer visible and infrared wavelengths up to about 4.5 micrometres. Natural rutile may contain up to 10% iron and significant amounts of niobium and tantalum.

Rutile derives its name from the Latin rutilus ('red'), in reference to the deep red color observed in some specimens when viewed by transmitted light. Rutile was first described in 1803 by Abraham Gottlob Werner using specimens obtained in Horcajuelo de la Sierra, Madrid (Spain), which is consequently the type locality. (Full article...)
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Tourmaline (/ˈtʊərməlɪn, -ˌliːn/ TOOR-mə-lin, -⁠leen) is a crystalline silicate mineral group in which boron is compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. This gemstone comes in a wide variety of colors.

The name is derived from the Sinhalese tōramalli (ටෝරමල්ලි), which refers to the carnelian gemstones. (Full article...)
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Magnetite from Bolivia

Magnetite is a mineral and one of the main iron ores, with the chemical formula Fe²⁺Fe3+2O₄. It is one of the oxides of iron, and is ferrimagnetic; it is attracted to a magnet and can be magnetized to become a permanent magnet itself. With the exception of extremely rare native iron deposits, it is the most magnetic of all the naturally occurring minerals on Earth. Naturally magnetized pieces of magnetite, called lodestone, will attract small pieces of iron, which is how ancient peoples first discovered the property of magnetism.

Magnetite is black or brownish-black with a metallic luster, has a Mohs hardness of 5–6 and leaves a black streak. Small grains of magnetite are very common in igneous and metamorphic rocks.

The chemical IUPAC name is iron(II,III) oxide and the common chemical name is ferrous-ferric oxide. (Full article...)
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Graphite specimen

Graphite (/ˈɡræfaɪt/) is a crystalline allotrope (form) of the element carbon. It consists of many stacked layers of graphene, typically in the excess of hundreds of layers. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on a large scale (1.3 million metric tons per year in 2022) for uses in many critical industries including refractories (50%), lithium-ion batteries (18%), foundries (10%), lubricants (5%), among others (17%). Under extremely high pressures and extremely high temperatures it converts to diamond. Graphite's low cost, thermal and chemical inertness and characteristic conductivity of heat and electricity finds numerous applications in high energy and high temperature processes. (Full article...)
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Intergrowth of lustrous, cubic crystals of pyrite, with some surfaces showing characteristic striations, from Huanzala mine, Ancash, Peru. Specimen size: 7.0 × 5.0 × 2.5 cm

The mineral pyrite (/ˈpaɪraɪt/ PY-ryte), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula FeS₂ (iron (II) disulfide). Pyrite is the most abundant sulfide mineral.
Pyrite's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of fool's gold. The color has also led to the nicknames brass, brazzle, and brazil, primarily used to refer to pyrite found in coal.

The name pyrite is derived from the Greek πυρίτης λίθος (pyritēs lithos), 'stone or mineral which strikes fire', in turn from πῦρ (pŷr), 'fire'. In ancient Roman times, this name was applied to several types of stone that would create sparks when struck against steel; Pliny the Elder described one of them as being brassy, almost certainly a reference to what is now called pyrite.

By Georgius Agricola's time, c. 1550, the term had become a generic term for all of the sulfide minerals. (Full article...)
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Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO₄·2H₂O. It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk chalk. Gypsum also crystallizes as translucent crystals of selenite. It forms as an evaporite mineral and as a hydration product of anhydrite. The Mohs scale of mineral hardness defines gypsum as hardness value 2 based on scratch hardness comparison.

Fine-grained white or lightly tinted forms of gypsum known as alabaster have been used for sculpture by many cultures including Ancient Egypt, Mesopotamia, Ancient Rome, the Byzantine Empire, and the Nottingham alabasters of Medieval England. (Full article...)
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The diamond crystal structure belongs to the face-centered cubic lattice, with a repeated two-atom pattern.

In crystallography, a crystal system is a set of point groups (a group of geometric symmetries with at least one fixed point). A lattice system is a set of Bravais lattices. Space groups are classified into crystal systems according to their point groups, and into lattice systems according to their Bravais lattices. Crystal systems that have space groups assigned to a common lattice system are combined into a crystal family.

The seven crystal systems are triclinic, monoclinic, orthorhombic, tetragonal, trigonal, hexagonal, and cubic. Informally, two crystals are in the same crystal system if they have similar symmetries (though there are many exceptions). (Full article...)
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Kaolinite (/ˈkeɪ.ələˌnaɪt, -lɪ-/ KAY-ə-lə-nyte, -⁠lih-; also called kaolin) is a clay mineral, with the chemical composition: Al₂Si₂O₅(OH)₄. It is a layered silicate mineral, with one tetrahedral sheet of silica (SiO₄) linked through oxygen atoms to one octahedral sheet of alumina (AlO₆).

Kaolinite is a soft, earthy, usually white, mineral (dioctahedral phyllosilicate clay), produced by the chemical weathering of aluminium silicate minerals like feldspar. It has a low shrink–swell capacity and a low cation-exchange capacity (1–15 meq/100 g).

Rocks that are rich in kaolinite, and halloysite, are known as kaolin (/ˈkeɪ.əlɪn/) or china clay. In many parts of the world kaolin is colored pink-orange-red by iron oxide, giving it a distinct rust hue. Lower concentrations of iron oxide yield the white, yellow, or light orange colors of kaolin. Alternating lighter and darker layers are sometimes found, as at Providence Canyon State Park in Georgia, United States.

Kaolin is an important raw material in many industries and applications. Commercial grades of kaolin are supplied and transported as powder, lumps, semi-dried noodle or slurry. Global production of kaolin in 2021 was estimated to be 45 million tonnes, with a total market value of US $4.24 billion. (Full article...)
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Beachy Head is a part of the extensive Southern England Chalk Formation.

Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. Chalk is common throughout Western Europe, where deposits underlie parts of France, and steep cliffs are often seen where they meet the sea in places such as the Dover cliffs on the Kent coast of the English Channel.

Chalk is mined for use in industry, such as for quicklime, bricks and builder's putty, and in agriculture, for raising pH in soils with high acidity. It is also used for "blackboard chalk" for writing and drawing on various types of surfaces, although these can also be manufactured from other carbonate-based minerals, or gypsum. (Full article...)
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Micas (/ˈmaɪkəz/ MY-kəz) are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into fragile elastic plates. This characteristic is described as perfect basal cleavage. Mica is common in igneous and metamorphic rock and is occasionally found as small flakes in sedimentary rock. It is particularly prominent in many granites, pegmatites, and schists, and "books" (large individual crystals) of mica several feet across have been found in some pegmatites.

Micas are used in products such as drywalls, paints, and fillers, especially in parts for automobiles, roofing, and in electronics. The mineral is used in cosmetics and food to add "shimmer" or "frost". (Full article...)
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Halite from the Wieliczka salt mine, Małopolskie, Poland

Halite (/ˈhælaɪt, ˈheɪlaɪt/ HAL-yte, HAY-lyte), commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride (NaCl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pink, red, orange, yellow or gray depending on inclusion of other materials, impurities, and structural or isotopic abnormalities in the crystals. It commonly occurs with other evaporite deposit minerals such as several of the sulfates, halides, and borates. The name halite is derived from the Ancient Greek word for "salt", ἅλς (háls). (Full article...)
Image 21

Brazilian trigonal hematite crystal

Hematite (/ˈhiːməˌtaɪt, ˈhɛmə-/), also spelled as haematite, is a common iron oxide compound with the formula, Fe₂O₃ and is widely found in rocks and soils. Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of Fe
₂O
₃. It has the same crystal structure as corundum (Al
₂O
₃) and ilmenite (FeTiO
₃). With this it forms a complete solid solution at temperatures above 950 °C (1,740 °F).

Hematite occurs naturally in black to steel or silver-gray, brown to reddish-brown, or red colors. It is mined as an important ore mineral of iron. It is electrically conductive. Hematite varieties include kidney ore, martite (pseudomorphs after magnetite), iron rose and specularite (specular hematite). While these forms vary, they all have a rust-red streak. Hematite is not only harder than pure iron, but also much more brittle. Maghemite is a polymorph of hematite (γ-Fe
₂O
₃) with the same chemical formula, but with a spinel structure like magnetite.

Large deposits of hematite are found in banded iron formations. Gray hematite is typically found in places that have still, standing water, or mineral hot springs, such as those in Yellowstone National Park in North America. The mineral may precipitate in the water and collect in layers at the bottom of the lake, spring, or other standing water. Hematite can also occur in the absence of water, usually as the result of volcanic activity.

Clay-sized hematite crystals also may occur as a secondary mineral formed by weathering processes in soil, and along with other iron oxides or oxyhydroxides such as goethite, which is responsible for the red color of many tropical, ancient, or otherwise highly weathered soils. (Full article...)
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Deep green isolated fluorite crystal resembling a truncated octahedron, set upon a micaceous matrix, from Erongo Mountain, Erongo Region, Namibia (overall size: 50 mm × 27 mm, crystal size: 19 mm wide, 30 g)

Fluorite (also called fluorspar) is the mineral form of calcium fluoride, CaF₂. It belongs to the halide minerals. It crystallizes in isometric cubic habit, although octahedral and more complex isometric forms are not uncommon.

The Mohs scale of mineral hardness, based on scratch hardness comparison, defines value 4 as fluorite.

Pure fluorite is colourless and transparent, both in visible and ultraviolet light, but impurities usually make it a colorful mineral and the stone has ornamental and lapidary uses. Industrially, fluorite is used as a flux for smelting, and in the production of certain glasses and enamels. The purest grades of fluorite are a source of fluoride for hydrofluoric acid manufacture, which is the intermediate source of most fluorine-containing fine chemicals. Optically clear transparent fluorite has anomalous partial dispersion, that is, its refractive index varies with the wavelength of light in a manner that differs from that of commonly used glasses, so fluorite is useful in making apochromatic lenses, and particularly valuable in photographic optics. Fluorite optics are also usable in the far-ultraviolet and mid-infrared ranges, where conventional glasses are too opaque for use. Fluorite also has low dispersion, and a high refractive index for its density. (Full article...)
Image 23

Three varieties of beryl (left to right): morganite, aquamarine and emerald

Beryl (/ˈbɛrəl/ BERR-əl) is a mineral composed of beryllium aluminium silicate with the chemical formula Be₃Al₂Si₆O₁₈. Well-known varieties of beryl include emerald and aquamarine. Naturally occurring hexagonal crystals of beryl can be up to several meters in size, but terminated crystals are relatively rare. Pure beryl is colorless, but it is frequently tinted by impurities; possible colors are green, blue, yellow, pink, and red (the rarest). It is an ore source of beryllium. (Full article...)
Image 24
Crystal structure of table salt (sodium in purple, chlorine in green)

In crystallography, crystal structure is a description of ordered arrangement of atoms, ions, or molecules in a crystalline material. Ordered structures occur from intrinsic nature of constituent particles to form symmetric patterns that repeat along the principal directions of three-dimensional space in matter.

The smallest group of particles in material that constitutes this repeating pattern is unit cell of the structure. The unit cell completely reflects symmetry and structure of the entire crystal, which is built up by repetitive translation of unit cell along its principal axes. The translation vectors define the nodes of Bravais lattice.

The lengths of principal axes/edges, of unit cell and angles between them are lattice constants, also called lattice parameters or cell parameters. The symmetry properties of crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space may be described by 230 space groups.

The crystal structure and symmetry play a critical role in determining many physical properties, such as cleavage, electronic band structure, and optical transparency. (Full article...)
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A natural diamond crystal

Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Diamond as a form of carbon is a tasteless, odourless, strong, brittle solid, colourless in pure form, a poor conductor of electricity, and insoluble in water. Another solid form of carbon known as graphite is the chemically stable form of carbon at room temperature and pressure, but diamond is metastable and converts to it at a negligible rate under those conditions. Diamond has the highest hardness and thermal conductivity of any natural material, properties that are used in major industrial applications such as cutting and polishing tools. They are also the reason that diamond anvil cells can subject materials to pressures found deep in the Earth.

Because the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions are boron and nitrogen). Small numbers of defects or impurities (about one per million of lattice atoms) can color a diamond blue (boron), yellow (nitrogen), brown (defects), green (radiation exposure), purple, pink, orange, or red. Diamond also has a very high refractive index and a relatively high optical dispersion.

Most natural diamonds have ages between 1 billion and 3.5 billion years. Most were formed at depths between 150 and 250 kilometres (93 and 155 mi) in the Earth's mantle, although a few have come from as deep as 800 kilometres (500 mi). Under high pressure and temperature, carbon-containing fluids dissolved various minerals and replaced them with diamonds. Much more recently (hundreds to tens of million years ago), they were carried to the surface in volcanic eruptions and deposited in igneous rocks known as kimberlites and lamproites.

Synthetic diamonds can be grown from high-purity carbon under high pressures and temperatures or from hydrocarbon gases by chemical vapor deposition (CVD). Imitation diamonds can also be made out of materials such as cubic zirconia and silicon carbide. Natural, synthetic, and imitation diamonds are most commonly distinguished using optical techniques or thermal conductivity measurements. (Full article...)

Mineralogista seleccionado

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Brøgger en 1922

Waldemar Christofer Brøgger ForMemRS FRSE (10 de noviembre de 1851 – 17 de febrero de 1940) fue un geólogo y mineralogista noruego . Sus investigaciones sobre las rocas ígneas del Pérmico (hace entre 286 y 245 millones de años) del distrito de Oslo hicieron avanzar enormemente la teoría petrológica sobre la formación de las rocas . ( Artículo completo... )
Image 2

Adolf Erik Nordenskiöld

Nils Adolf Erik Nordenskiöld (; 18 November 1832 – 12 August 1901) was a Finland-Swedish aristocrat, geologist, mineralogist and Arctic explorer. He was a member of the noble Nordenskiöld family of scientists and held the title of a friherre (baron).

Born in the Grand Duchy of Finland in the Russian Empire, he was forced to move to Sweden in 1857 due to his political activity, where he became a member of the Parliament of Sweden and of the Swedish Academy. He led the Vega Expedition along the northern coast of Eurasia in 1878–1879. This was the first complete crossing of the Northeast Passage. Initially a troubled enterprise, the successful expedition is considered to be among the highest achievements in the history of Swedish science. (Full article...)
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Prof Gustavus ("Gustav") Rose FRSFor HFRSE (18 March 1798 – 15 July 1873) was a German mineralogist who was a native of Berlin. He was President of the German Geological Society from 1863 to 1873. (Full article...)
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Ian Stuart Edward Carmichael FRS (29 March 1930 –26 August 2011) was a British-born American igneous petrologist and volcanologist who established extensive quantitative methods for research in the thermodynamics of magma. (Full article...)
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Forchhammer, c. 1850

Johan Georg Forchhammer (26 July 1794 – 14 December 1865) was a Danish mineralogist and geologist. (Full article...)
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Franz Ernst Brückmann (27 September 1697 – 21 March 1753) was a German mineralogist born at Marienthal near Helmstedt. Having qualified as a physician in 1721, he practised at Braunschweig and afterwards at Wolfenbüttel (from 1728). In 1747 he was appointed medical assessor in Braunschweig.

His leisure time was given up to natural history, and especially to mineralogy and botany. He appears to have been the first to introduce the term "oolithus" to rocks that resemble in structure the roe of a fish; whence the terms "oolite" and "oolitic". He died at Wolfenbüttel. (Full article...)
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Helen Dick Megaw (1 June 1907 – 26 February 2002) was an Irish crystallographer who was a pioneer in X-ray crystallography. She made measurements of the cell dimensions of ice and established the Perovskite crystal structure. (Full article...)
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William "Bill" Wallace Pinch (August 15, 1940 – April 1, 2017) was a mineralogist from Rochester, New York. The Mineralogical Association of Canada has an award named after him, the Pinch Medal, "to recognize major and sustained contributions to the advancement of mineralogy by members of the collector-dealer community."
The Pinch Medal has been awarded to a deserving mineralogist every other year since it was first awarded to Pinch in 2001, and is given at the Tucson Mineral Show in February.

Pinch was also a notable mineral collector. His collection was sold in 1989 to the Canadian Museum of Nature for $US 3.5 million, and will be documented in a book to be published in 2018. (Full article...)
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Johann Jakob Nöggerath.

Johann Jakob Nöggerath (also as Johann Jacob Noeggerath) (10 October 1788 – 13 September 1877), German mineralogist and geologist, was born at Bonn.

In 1814-1815 he became a commissioner of mines for some of the Rhine provinces, and in 1818 became an associate professor at the newly established University of Bonn. In 1821 he was named a full professor of mineralogy and mining sciences at Bonn, where he also served as director of the university's natural history museum. He obtained a very fine collection of minerals for the museum, was eminently successful as a teacher, and achieved a wide reputation among mining engineers. (Full article...)
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Joseph (Joe) Anthony Mandarino OC, FRSC (20 April 1929 in Chicago, Illinois – 19 September 2007) was an American-Canadian mineralogist and crystallographer. (Full article...)
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Friedrich Rinne

Friedrich Wilhelm Berthold Rinne (16 March 1863 in Osterode am Harz – 12 March 1933 in Freiburg im Breisgau) was a German mineralogist, crystallographer and petrographer. (Full article...)
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Douglas Saxon Coombs CNZM (23 November 1924 – 23 December 2016) was a New Zealand mineralogist and petrologist. (Full article...)
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Alfred Des Cloizeaux

Alfred Louis Olivier Legrand Des Cloizeaux (17 October 1817 – 6 May 1897) was a French mineralogist.

Des Cloizeaux was born at Beauvais, in the department of Oise. He studied with Jean-Baptiste Biot at the Collège de France. He became professor of mineralogy at the École Normale Supérieure and afterwards at the Muséum National d'Histoire Naturelle in Paris. He studied the geysers of Iceland, and wrote also on the classification of some of the eruptive rocks. (Full article...)
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Lettsom caricatured as the diplomat 'Tapeworm' (centre, standing): pencil sketch by William Makepeace Thackeray

William Garrow Lettsom FRAS (1805 – 14 December 1887) was a British diplomat and scientist. He was instrumental in revealing the text of the secret Treaty of the Triple Alliance between Argentina, the Empire of Brazil and Uruguay. (Full article...)
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Marcel Alexandre Bertrand

Marcel Alexandre Bertrand (2 July 1847 – 13 February 1907) was a French geologist born in Paris. He was the son of mathematician Joseph Louis François Bertrand (1822–1900), and son-in-law to physicist Éleuthère Mascart (1837-1908).

He studied at the École Polytechnique, and beginning in 1869 he attended the Ecole des Mines de Paris. From 1877 he carried out geological mapping studies of Provence, the Jura Mountains and the Alps. In 1886, he became an instructor at the École Nationale Supérieure des Mines, and in 1896 became a member of the Académie des sciences. (Full article...)
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Stanley Robert Mitchell (12 February 1881 – 22 March 1963) was an Australian commercial metallurgist as well as an amateur mineralogist and ethnologist. (Full article...)
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Konrad Oebbeke (2 November 1853, Hildesheim – 1 February 1932) was a German geologist and mineralogist.

He studied at the Universities of Heidelberg and Erlangen, obtaining his doctorate at the University of Würzburg in 1877. Afterwards he worked as an assistant to the Geological Survey of Bavaria. He served as privat-docent at the University of Munich, later becoming a professor of mineralogy and geology at Erlangen (1887).
From 1895 to 1927 he was a professor at the Technische Hochschule of Munich. (Full article...)
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Daubenton in 1791

Louis Jean-Marie Daubenton (29 May 1716 – 1 January 1800) was a French naturalist and contributor to the Encyclopédie ou Dictionnaire raisonné des sciences, des arts et des métiers. (Full article...)
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Alexander Karl von Kraatz-Koschlau (24 June 1867 – 18 May 1900) was a German geologist.

Karl von Kraatz-Koschlau was born in Reichenbach near Stettin. He studied philosophy and sciences in Freiburg and Munich, where he obtained his doctorate with a dissertation on tartaric acid and its salts (1892). Afterwards he was assigned to the mineralogical institute in Munich. One of his scientific excursions during this time period involved geological research of the Serra de Monchique in the Algarve. (Full article...)
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Marble relief of Schrauf in the Arkadenhof, University of Vienna

Albrecht Schrauf (14 December 1837, Vienna – 29 November 1897, Vienna) was an Austrian mineralogist and crystallographer. (Full article...)
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William Niven, mineralogist, circa 1895

William Niven (2 October 1850 – 2 June 1937) was a mineralogist and archeologist noted for his discovery of the minerals yttrialite, thorogummite, aguilarite and nivenite (named after him), as well as a set of controversial tablets. Originally from Scotland, Niven came to the United States in 1879, where he became heavily involved in mineralogy and mining. (Full article...)
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William Hallowes Miller

Prof William Hallowes Miller FRS HFRSE LLD DCL (6 April 1801 – 20 May 1880) was a Welsh mineralogist and laid the foundations of modern crystallography.

Miller indices are named after him, the method having been described in his Treatise on Crystallography (1839). The mineral known as millerite is named after him. (Full article...)
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Parker Cleaveland (January 1, 1780 – August 15, 1858) was an American geologist and mineralogist, born in Rowley, Massachusetts.

He was identified with the early progress of the natural sciences. After having attending the Dummer Academy in Byfield, Massachusetts, he graduated from Harvard in 1799, was tutor in mathematics there from 1803 to 1805, was chosen professor of mathematics and natural philosophy and lecturer on chemistry and mineralogy in Bowdoin College, a position which he retained until his death, although many professorships in other colleges and the presidency of his own were offered to him. He was elected an Associate Fellow of the American Academy of Arts and Sciences in 1809 and to the American Philosophical Society in 1818. (Full article...)
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Archibald Bruce (February 1777 – February 22, 1818) was an American physician and mineralogist. (Full article...)
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Leonid Alekseyevich Kulik (Russian: Леонид Алексеевич Кулик; 19 August 1883 – 14 or 24 April 1942) was a Soviet mineralogist who is noted for his research into meteorites. (Full article...)

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Para obtener recursos para el editor y colaborar con otros editores para mejorar los artículos de Wikipedia relacionados con Minerales, consulte WikiProject Rocas y minerales .

Imágenes generales

Las siguientes son imágenes de varios artículos relacionados con minerales en Wikipedia.

Image 1Escala de Mohs versus dureza absoluta (de Mineral )
Image 2Rosa del desierto de yeso (de Mineral )
Image 3Cristal de esfalrita parcialmente envuelto en calcita de la Formación Milwaukee del Devónico de Wisconsin (de Mineral )
Image 4La aegirina , un clinopiroxeno de hierro y sodio, es parte de la subclase de inosilicatos. (de Mineral )
Image 5La pirita tiene un brillo metálico. (del Mineral )
Image 6Hübnerita , el miembro final rico en manganeso de la serie de la wolframita , con un poco de cuarzo en el fondo (de Mineral )
Image 7La epidota suele tener un color verde pistacho característico. (de Mineral )
Image 8Pirita (de Lustre (mineralogía) )
Image 9Cinabrio rojo (HgS), un mineral de mercurio, sobre dolomita. (de Mineral )
Image 10El topacio tiene una forma cristalina alargada ortorrómbica característica. (del Mineral )
Image 11 Tremolita asbestiforme , parte del grupo de los anfíboles en la subclase de inosilicatos (de Mineral )
Image 12Escisión basal perfecta como se ve en la biotita (negra) y buena escisión vista en la matriz ( ortoclasa rosa ). (de Mineral )
Image 13La galena , PbS, es un mineral con una gravedad específica alta. (de Mineral )
Image 14Moscovita, una especie mineral del grupo de las micas, dentro de la subclase de los filosilicatos (de Mineral )
Image 15El diamante es el material natural más duro y tiene una dureza Mohs de 10. (de Mineral )
Image 16Kit de dureza de Mohs, que contiene una muestra de cada mineral en la escala de dureza de diez puntos (de la escala de Mohs )
Image 17La carnotita (amarilla) es un mineral que contiene uranio radiactivo . (de Mineral )
Image 18Maclas de contacto, como se observa en la espinela (de Mineral )
Image 19Cristales cúbicos rosados de halita (NaCl; clase de haluro) sobre una matriz de nahcolita (NaHCO ₃ ; un carbonato y una forma mineral de bicarbonato de sodio, utilizado como bicarbonato de sodio ). (de Mineral )
Image 20Cuando los minerales reaccionan, los productos a veces adoptan la forma del reactivo; el mineral producto se denomina pseudomorfo del reactivo (o posterior a él). Aquí se ilustra un pseudomorfo de caolinita posterior a la ortoclasa . Aquí, el pseudomorfo conserva la macla de Carlsbad común en la ortoclasa. (de Mineral )
Image 21Cristales de serandita , natrolita , analcima y aegirina de Mont Saint-Hilaire, Quebec, Canadá (de Mineral )
Image 22El esquisto es una roca metamórfica que se caracteriza por una abundancia de minerales laminares. En este ejemplo, la roca tiene porfiroblastos de silimanita prominentes de hasta 3 cm (1,2 pulgadas). (de Mineral )
Image 23Andradita negra, un miembro terminal del grupo de los granates ortosilicatados. (de Mineral )
Image 24Un ejemplo de elbaíta, una especie de turmalina, con bandas de color distintivas. (de Mineral )
Image 25Oro nativo. Raro ejemplar de cristales robustos que crecen sobre un tallo central, de tamaño 3,7 x 1,1 x 0,4 cm, procedente de Venezuela. (de Mineral )
Image 26La natrolita es una serie mineral del grupo de las zeolitas; esta muestra tiene un hábito cristalino acicular muy prominente. (de Mineral )

Sabías ...?

... que el raro mineral Matlockita ( PbFCl ) (en la foto) recibe su nombre de una ciudad de Derbyshire ?
...que el mineral de fosfato amorfo santabarbaraita debe su nombre al distrito minero italiano de Santa Bárbara, donde fue descubierto en 2003, pero su nombre también honra a Santa Bárbara , la santa patrona de los mineros ?
...que cuando los cristales amarillos de mosesita , un mineral muy raro que se encuentra en depósitos de mercurio , se calientan a 186 °C (367 °F), se vuelven isotrópicos ?