Portal:Minerales

Temas del portal: Actividades; Cultura; Geografía; Salud; Historia; Matemáticas; Naturaleza; Gente; Filosofía; Religión; Sociedad; Tecnología; Portal aleatorio

El Portal de los Minerales

En geología y mineralogía , un mineral o especie mineral es, a grandes rasgos, 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 normalmente excluye 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 de la química (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 del de roca , que es cualquier material geológico sólido a granel que es relativamente homogéneo a una escala suficientemente grande. Una roca puede consistir en un tipo de mineral o puede ser un agregado de dos o más tipos diferentes de minerales, segregados espacialmente en distintas fases .

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 produce naturalmente con diferentes estructuras cristalinas, cada estructura se considera una especie mineral diferente. Así, por ejemplo, el cuarzo y la stishovita son dos minerales diferentes formados por el mismo compuesto, el dióxido de silicio . ( Articulo completo... )

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

Actualizar con nuevas selecciones a continuación (purgar)

Artículos seleccionados

Image 1

Tres variedades de berilo (de izquierda a derecha): morganita , aguamarina y esmeralda.

Berilo ( / ˈbɛrəl / BERR - əl ) es un mineral compuesto de silicato de berilio y aluminio con la fórmula química Be₃ Al₂ Si₆ O₁₈ . Las variedades más conocidas de berilo incluyen la esmeralda y la aguamarina . Los cristales hexagonales de berilo que se encuentran naturalmente pueden tener un tamaño de hasta varios metros, pero los cristales terminados son relativamente raros. El berilo puro es incoloro, pero frecuentemente está teñido por impurezas; Los colores posibles son verde, azul, amarillo, rosa y rojo (el más raro). Es una fuente mineral de berilio . ( Articulo completo... )
Image 2

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 (also written as Na₂B₄O₇·10H₂O).

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...)
Image 3

Fibrous tremolite asbestos on muscovite

Asbestos (/æsˈbɛstəs, æz-, -tɒs/ ass-BES-təs, az-, -⁠toss) is a naturally occurring fibrous silicate mineral. 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 across the world as a building material, until its adverse effects on human health were more widely 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, at least 100,000 people are thought to die each year from diseases related to asbestos exposure.^{[citation needed]} 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 to 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...)
Image 4

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 5

Garnets ( /ˈɡɑːrnɪt/) are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives.

All species of garnets possess similar physical properties and crystal forms, but differ in chemical composition. The different species are pyrope, almandine, spessartine, grossular (varieties of which are hessonite or cinnamon-stone and tsavorite), uvarovite and andradite. The garnets make up two solid solution series: pyrope-almandine-spessartine (pyralspite), with the composition range [Mg,Fe,Mn]₃Al₂(SiO₄)₃; and uvarovite-grossular-andradite (ugrandite), with the composition range Ca₃[Cr,Al,Fe]₂(SiO₄)₃. (Full article...)
Image 6
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 (albeit there are many exceptions). (Full article...)
Image 7

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...)
Image 8

Dolomite (white) on talc

Dolomite (/ˈdɒl.əˌmaɪt, ˈdoʊ.lə-/) is an anhydrous carbonate mineral composed of calcium magnesium carbonate, ideally CaMg(CO₃)₂. The term is also used for a sedimentary carbonate rock composed mostly of the mineral dolomite (see Dolomite (rock)). An alternative name sometimes used for the dolomitic rock type is dolostone. (Full article...)
Image 9

A naturally-cut diamond crystal

Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. 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...)
Image 10
Crystal structure of table salt (sodium in purple, chlorine in green)

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

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

The lengths of the principal axes, or edges, of the unit cell and the angles between them are the lattice constants, also called lattice parameters or cell parameters. The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space may be described by the 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...)
Image 11
Mineralogy applies principles of chemistry, geology, physics and materials science to the study of minerals

Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical) properties of minerals and mineralized artifacts. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as well as their utilization. (Full article...)
Image 12

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 glases, so fluorite is useful in making apochromatic lenses, making it valuable, particularly 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, which can make it useful for some specialized purposes in optics. (Full article...)
Image 13

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...)
Image 14

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 (pyr), '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...)
Image 15

Cinnabar (/ˈsɪnəˌbɑːr/; from Ancient Greek κιννάβαρι (kinnábari)), or cinnabarite (/ˌsɪnəˈbɑːraɪt/), also known as mercurblende is the bright scarlet to brick-red form of mercury(II) sulfide (HgS). It is the most common source ore for refining elemental mercury and is the historic source for the brilliant red or scarlet pigment termed vermilion and associated red mercury pigments.

Cinnabar generally occurs as a vein-filling mineral associated with volcanic activity and alkaline hot springs. The mineral resembles quartz in symmetry and it exhibits birefringence. Cinnabar has a mean refractive index near 3.2, a hardness between 2.0 and 2.5, and a specific gravity of approximately 8.1. The color and properties derive from a structure that is a hexagonal crystalline lattice belonging to the trigonal crystal system, crystals that sometimes exhibit twinning.

Cinnabar has been used for its color since antiquity in the Near East, including as a rouge-type cosmetic, in the New World since the Olmec culture, and in China since as early as the Yangshao culture, where it was used in coloring stoneware.

Associated modern precautions for the use and handling of cinnabar arise from the toxicity of the mercury component, which was recognized as early as ancient Rome. (Full article...)
Image 16
Zeolite exhibited in the Estonian Museum of Natural History

Zeolite is a family of several microporous, crystalline aluminosilicate materials commonly used as commercial adsorbents and catalysts. They mainly consist of silicon, aluminium, oxygen, and have the general formula Mⁿ⁺
_1/n(AlO
₂)⁻
(SiO
₂)
_x･yH
₂O where Mⁿ⁺
_1/n is either a metal ion or H⁺. These positive ions can be exchanged for others in a contacting electrolyte solution. H⁺
exchanged zeolites are particularly useful as solid acid catalysts.

The term was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt, who observed that rapidly heating a material, believed to have been stilbite, produced large amounts of steam from water that had been adsorbed by the material. Based on this, he called the material zeolite, from the Greek ζέω (zéō), meaning "to boil" and λίθος (líthos), meaning "stone".

Zeolites occur naturally, but are also produced industrially on a large scale. , 253 unique zeolite frameworks have been identified, and over 40 naturally occurring zeolite frameworks are known. Every new zeolite structure that is obtained is examined by the International Zeolite Association Structure Commission (IZA-SC) and receives a three-letter designation. (Full article...)
Image 17

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...)
Image 18

Micas (/ˈmaɪkəz/ MY-kəz) are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into extremely thin 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, fillers, especially in parts for automobiles, roofing and shingles, as well as in electronics. The mineral is used in cosmetics and food to add "shimmer" or "frost." (Full article...)
Image 19
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...)
Image 20

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 naturally occurs 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 can 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 can also 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...)
Image 21
A rock containing three crystals of pyrite (FeS₂). The crystal structure of pyrite is primitive cubic, and this is reflected in the cubic symmetry of its natural crystal facets.

In crystallography, the cubic (or isometric) crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals.

There are three main varieties of these crystals:
- Primitive cubic (abbreviated cP and alternatively called simple cubic)
- Body-centered cubic (abbreviated cI or bcc)
- Face-centered cubic (abbreviated cF or fcc)
Note: the term fcc is often used in synonym for the cubic close-packed or ccp structure occurring in metals. However, fcc stands for a face-centered-cubic Bravais lattice, which is not necessarily close-packed when a motif is set onto the lattice points. E.g. the diamond and the zincblende lattices are fcc but not close-packed.
Each is subdivided into other variants listed below. Although the unit cells in these crystals are conventionally taken to be cubes, the primitive unit cells often are not. (Full article...)
Image 22

Amethyst cluster from Artigas, Uruguay

Amethyst is a violet variety of quartz. The name comes from the Koine Greek αμέθυστος amethystos from $α-$ a-, "not" and $μεθύσκω$ (Ancient Greek) methysko / $μεθώ$ metho (Modern Greek), "intoxicate", a reference to the belief that the stone protected its owner from drunkenness. Ancient Greeks wore amethyst and carved drinking vessels from it in the belief that it would prevent intoxication.

Amethyst, a semiprecious stone, is often used in jewelry. (Full article...)
Image 23

A ruby crystal from Dodoma Region, Tanzania

A ruby is a pinkish red to blood-red colored gemstone, a variety of the mineral corundum (aluminium oxide). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called sapphires. Ruby is one of the traditional cardinal gems, alongside amethyst, sapphire, emerald, and diamond. The word ruby comes from ruber, Latin for red. The color of a ruby is due to the element chromium.

Some gemstones that are popularly or historically called rubies, such as the Black Prince's Ruby in the British Imperial State Crown, are actually spinels. These were once known as "Balas rubies".

The quality of a ruby is determined by its color, cut, and clarity, which, along with carat weight, affect its value. The brightest and most valuable shade of red, called blood-red or pigeon blood, commands a large premium over other rubies of similar quality. After color follows clarity: similar to diamonds, a clear stone will command a premium, but a ruby without any needle-like rutile inclusions may indicate that the stone has been treated. Ruby is the traditional birthstone for July and is usually pinker than garnet, although some rhodolite garnets have a similar pinkish hue to most rubies. The world's most valuable ruby to be sold at auction is the Sunrise Ruby. (Full article...)
Image 24

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...)
Image 25

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 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...)

Mineralogista seleccionado

Image 1

Giuseppe Giovanni Antonio Meneghini (30 de julio de 1811, Padua - 29 de enero de 1889, Pisa ) fue un botánico , geólogo y paleontólogo italiano . ( Articulo completo... )
Image 2
Franz Ambrosius Reuss (3 October 1761 – 9 September 1830) was a Czech geologist, mineralogist and balneologist. He was the father of geologist August Emanuel von Reuss. (Full article...)
Image 3
William Alexander (Alex) Deer FRS (26 October 1910 – 8 February 2009) was a distinguished British geologist, petrologist and mineralogist. (Full article...)
Image 4

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...)
Image 5

Robert Miller Hazen (born November 1, 1948) is an American mineralogist and astrobiologist. He is a research scientist at the Carnegie Institution of Washington's Geophysical Laboratory and Clarence Robinson Professor of Earth Science at George Mason University, in the United States. Hazen is the Executive Director of the Deep Carbon Observatory. (Full article...)
Image 6
Werner Schreyer (14 November 1930 in Nuremberg; 12 February 2006 in Bochum) was a German mineralogist and experimental metamorphic petrologist. Schreyer completed his undergraduate work in geology and petrology at the University of Erlangen-Nuremberg, obtained his doctorate from the University of Munich in 1957, and in 1966 received his Habilitation from the University of Kiel. He was a professor at Ruhr University Bochum from 1966 to 1996. In 2002 Schreyer became the first German to be awarded the Mineralogical Society of America's highest honor, the Roebling Medal. Schreyer was a leading expert on phase relations in the MgO–Al₂O₃–SiO₂–H₂O (MASH) system, specializing in cordierite and minerals with equivalent chemical compositions, and high pressure and ultra high-pressure metamorphic mineral assemblages.

The mineral Schreyerite (V2Ti3O9) was named after Schreyer. (Full article...)
Image 7
Leonard James Spencer CBE FRS (7 July 1870 – 14 April 1959) was a British geologist. He was an Honorary member of the Royal Geological Society of Cornwall, and also a recipient of its Bolitho Medal. He was president of the Mineralogical Society of Great Britain and Ireland from 1936 to 1939. In mineralogy, Spencer was an original investigator who described several new minerals, including miersite, tarbuttite and parahopeite. He also did important work as a curator, editor and bibliographer. He was the third person to receive the Roebling Medal, the highest award of the Mineralogical Society of America. In 1937, he was awarded the Murchison Medal of the Geological Society of London. He wrote at least 146 articles for the Encyclopædia Britannica Eleventh Edition.

His daughter, Penelope Spencer became a successful free-style dancer and choreographer. (Full article...)
Image 8
Ernest (Ernie) Henry Nickel (born Ernst Heinrich Nickel on 31 August 1925 in Louth, Ontario, died on 18 July 2009) was a mineralogist from Canada who emigrated to Australia. He is best known as an editor of the ninth edition of the Nickel-Strunz classification together with Karl Hugo Strunz. (Full article...)
Image 9
William Sefton Fyfe, CC FRSC FRS FRSNZ (4 June 1927 – 11 November 2013) was a New Zealand geologist and Professor Emeritus in the department of Earth Sciences at the University of Western Ontario. He is widely considered among the world's most eminent geochemists. (Full article...)
Image 10
Coat of Arms of the Chatelet/Chastelet family.

Jean du Chatelet, also known as Baron de Beausoleil and Auffembach (1578, Brabant – c. 1645, The Bastille, Paris), was a mineralogist, mining engineer and dowser. (Full article...)
Image 11

Thomas Egleston (December 9, 1832 – January 15, 1900) was an American engineer who helped found Columbia University's School of Mines, now the Fu Foundation School of Engineering and Applied Science. Throughout his lifetime, Egleston published numerous lectures and books on metallurgy. Many of his books are preserved today at the archive in the Library of Congress. (Full article...)
Image 12
Augustin-Alexis Damour

Augustin Alexis Damour (19 July 1808, in Paris – 22 September 1902, in Paris) was a French mineralogist who was also interested in prehistory. (Full article...)
Image 13
Carl Adolf Ferdinand Hintze (17 August 1851, Breslau – 28 December 1916, Breslau) was a German mineralogist and crystallographer.

From 1868 he studied at the University of Breslau, where he was a student of Ferdinand von Roemer. He then furthered his education at the universities of Bonn and Berlin. Beginning in 1872 he served as an assistant to mineralogist Paul Heinrich von Groth at the University of Strasbourg. In 1875, eye problems along with financial issues forced him to abandon his scientific activity at the university, and he subsequently found employment as a trader in the minerals business. Since 1880 he worked as a scientific director for a private firm in Bonn. (Full article...)
Image 14
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...)
Image 15
François Alluaud (21 September 1778, Limoges – 18 February 1866, Limoges) was a French manufacturer of Limoges porcelain, geologist and mineralogist. He was the grandfather of entomologist Charles Alluaud (1861–1949).

Following the death of his father in 1799, who was also named François Alluaud, he took over ownership of the family porcelain factory in Limoges. The company operated its own quarries; a feldspar mine at Chanteloube and a kaolin quarry at Marcognac. (Full article...)
Image 16

Escher (1945)

Berend George Escher (4 April 1885 – 11 October 1967) was a Dutch geologist.

Escher had a broad interest, but his research was mainly on crystallography, mineralogy and volcanology. He was a pioneer in experimental geology. He was a half-brother of the artist M. C. Escher, and had some influence on his work due to his knowledge of crystallography. M.C. Escher created a woodcut ex libris for his brother 'Beer' with a stylized image of a volcano around 1922 (Bool number 91). (Full article...)
Image 17
Bust of Frederic Cailliaud

Frédéric Cailliaud (9 June 1787 – 1 May 1869) was a French naturalist, mineralogist and conchologist. He was born, and died, in Nantes, where he was the curator of the Natural History Museum of Nantes from 1836 to 1869.

He travelled in Egypt, Nubia, and Ethiopia, collecting minerals and making observations. He was a part of the military expedition that his patron Viceroy Muhammad Ali sent south to conquer the Kingdom of Sennar, but also marched further into Fazogli where Caillaud searched for outcroppings of gold while the commander Ismail, son of Muhammad Ali, enslaved locals and slaughtered all who resisted him. Although he failed to find any sizeable deposits of gold in the mountains along the modern Sudan-Ethiopia border, he did make a sufficiently detailed survey of the area to be published after he returned to France in 1827. (Full article...)
Image 18

Gerardus Troost (March 5, 1776 – August 14, 1850) was a Dutch-American medical doctor, naturalist, mineralogist, and founding member and first president of the Philadelphia Academy of Natural Sciences. (Full article...)
Image 19

Relief portrait on the Werner building in Freiberg

Johann Friedrich August Breithaupt (May 16, 1791 – September 22, 1873) was a German mineralogist and professor at Freiberg Mining Academy in Freiberg, Saxony. (Full article...)
Image 20
Frank Rutley (14 May 1842 – 16 May 1904), an English geologist and petrographer, was born in Dover on 14 May 1842. He was educated partly in Bonn, but his interest in geology was kindled at the Royal School of Mines, where he studied from 1862 to 1864. He then joined the army, and served as lieutenant until 1867, when he became an Assistant Geologist on the Geological Survey.

Working in the Lake District, Rutley began to make a special study of rocks and rock-forming minerals, and soon qualified as acting petrographer on the Survey. For several years be worked in this capacity at the museum in Jermyn Street; he described the volcanic rocks of East Somerset and the Bristol district in 1876, and wrote special memoirs on The Eruptive Rocks of Brent Tor (1878) and on The Felsitic Lavas of England and Wales (1885). (Full article...)
Image 21
Bertram Eugene Warren (June 28, 1902 – June 27, 1991) was an American crystallographer. His studies of X-rays provided much knowledge and understanding of both crystalline and non-crystalline materials. He also worked on changing amorphous solids to a crystalline state. (Full article...)
Image 22
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 magmas. (Full article...)
Image 23

Arthur Moritz Schoenflies (German: [ˈʃøːnfliːs]; 17 April 1853 – 27 May 1928), sometimes written as Schönflies, was a German mathematician, known for his contributions to the application of group theory to crystallography, and for work in topology.

Schoenflies was born in Landsberg an der Warthe (modern Gorzów, Poland). Arthur Schoenflies married Emma Levin (1868–1939) in 1896. He studied under Ernst Kummer and Karl Weierstrass, and was influenced by Felix Klein. (Full article...)
Image 24
Otto Heinrich Erdmannsdörffer (11 March 1876, Heidelberg – 19 April 1955, Heidelberg) was a German mineralogist and petrographer, known for his analysis of rocks and minerals found in the Odenwald, the Black Forest and the Harz Mountains. He was the son of historian Bernhard Erdmannsdörffer.

He studied natural sciences at the universities of Heidelberg and Strasbourg, receiving his doctorate in 1900. For the next twelve years he worked as a research assistant at the Prussian Geological Survey, and in the meantime, obtained his habilitation in mineralogy and petrology from the University of Berlin (1908). In 1912 he was appointed chair of mineralogy and petrology at the Technical University of Hannover, and in 1926 returned to Heidelberg, where he succeeded Ernst Anton Wülfing as director of the mineralogical-petrographic institute. In 1932 he was named academic rector at Heidelberg. (Full article...)
Image 25
Arthur Connell FRS FRSE (30 November 1794 – 31 October 1863) was a Scottish chemist and mineralogist. The mineral Connellite is named after him. He was a Fellow of the Royal Society of London. (Full article...)

Portales relacionados

Involucrarse

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

Imágenes generales

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

Image 1Moscovita, una especie mineral del grupo de las mica, dentro de la subclase de filosilicatos (de Mineral )
Image 2La epidota suele tener un color verde pistacho distintivo. (de minerales )
Image 3La aegirina , un clinopiroxeno de hierro y sodio, forma parte de la subclase de inosilicato. (de minerales )
Image 4Pirita (de Lustre (mineralogía) )
Image 5La carnotita (amarilla) es un mineral radiactivo que contiene uranio . (de minerales )
Image 6El topacio tiene una característica forma de cristal alargada ortorrómbica. (de minerales )
Image 7Un ejemplo de elbaita, una especie de turmalina, con bandas de colores distintivas. (de minerales )
Image 8Oro nativo. Raro ejemplar de cristales robustos que crecen a partir de un tallo central, tamaño 3,7 x 1,1 x 0,4 cm, procedente de Venezuela. (de minerales )
Image 9Andradita negra, miembro final del grupo de los granates ortosilicatos. (de minerales )
Image 10Cuando los minerales reaccionan, los productos a veces adoptan la forma del reactivo; el mineral producto se denomina pseudomorfo de (o posterior) al reactivo. Aquí se ilustra un pseudomorfo de caolinita después de la ortoclasa . Aquí, el pseudomorfo conservó el hermanamiento de Carlsbad común en la ortoclasa. (de minerales )
Image 11Cristales de serandita , natrolita , analcima y aegirina del Mont Saint-Hilaire, Quebec, Canadá (de Mineral )
Image 12El diamante es el material natural más duro y tiene una dureza Mohs de 10 (de Mineral ).
Image 13Rosa del desierto de yeso (de Mineral )
Image 14Kit 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 15Perfecta escisión basal como se ve en la biotita (negro) y buena escisión en la matriz ( ortoclasa rosa ). (de minerales )
Image 16Galena , PbS, es un mineral con un peso específico elevado. (de minerales )
Image 17La natrolita es una serie de minerales del grupo de las zeolitas; este ejemplar tiene un hábito cristalino acicular muy prominente. (de minerales )
Image 18Cinabrio rojo (HgS), un mineral de mercurio, sobre dolomita. (de minerales )
Image 19La pirita tiene un brillo metálico. (de minerales )
Image 20El esquisto es una roca metamórfica caracterizada por una abundancia de minerales laminares. En este ejemplo, la roca tiene porfiroblastos de silimanita prominentes de hasta 3 cm (1,2 pulgadas). (de minerales )
Image 21 Tremolita asbestiforme , parte del grupo de anfíboles en la subclase de inosilicato (de Mineral )
Image 22Gemelos de contacto, como se ve en la espinela (de Mineral )
Image 23Cristales de halita cúbica rosa (NaCl; clase haluro) sobre una matriz de nahcolita (NaHCO ₃ ; un carbonato y forma mineral de bicarbonato de sodio, utilizado como bicarbonato de sodio ). (de minerales )
Image 24Hübnerita , el miembro final rico en manganeso de la serie de wolframita , con una menor cantidad de cuarzo al fondo (de Mineral )
Image 25Escala de Mohs versus dureza absoluta (de mineral )
Image 26Cristal de esfalerita parcialmente encerrado en calcita de la Formación Devónica Milwaukee de Wisconsin (de Mineral )

Sabías ...?

... que cuando se describió por primera vez el mineral paramelaconita (en la foto) , no se reconoció como una especie válida?
... que Karl Hugo Strunz fue el creador de la clasificación Nickel-Strunz ?
... que el Lapis Lacedaemonius , una roca volcánica conocida hoy sólo de una sola fuente, se ha utilizado como decoración en lugares tan alejados como Londres , Venecia y Palermo ?