The Minerals Portal
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.
The geological definition of mineral normally excludes compounds that occur only in living organisms. However, some minerals are often biogenic (such as calcite) or organic compounds in the sense of chemistry (such as mellite). Moreover, living organisms often synthesize inorganic minerals (such as hydroxylapatite) that also occur in rocks.
The concept of mineral is distinct from rock, which is any bulk solid geologic material that is relatively homogeneous at a large enough scale. A rock may consist of one type of mineral or may be an aggregate of two or more different types of minerals, spacially segregated into distinct phases.
Some natural solid substances without a definite crystalline structure, such as opal or obsidian, are more properly called mineraloids. If a chemical compound occurs naturally with different crystal structures, each structure is considered a different mineral species. Thus, for example, quartz and stishovite are two different minerals consisting of the same compound, silicon dioxide. (Full article...)
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...)
Selected articles
-
Image 1
Andesite (/ˈændəzaɪt/) is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predominantly of sodium-rich plagioclase plus pyroxene or hornblende.
Andesite is the extrusive equivalent of plutonic diorite. Characteristic of subduction zones, andesite represents the dominant rock type in island arcs. The average composition of the continental crust is andesitic. Along with basalts, andesites are a component of the Martian crust.
The name andesite is derived from the Andes mountain range, where this rock type is found in abundance. It was first applied by Christian Leopold von Buch in 1826. (Full article...) -
Image 2
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 3
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 its amorphous property, 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...) -
Image 4
Crystallography is the experimental science of determining the arrangement of atoms in crystalline solids. Crystallography is a fundamental subject in the fields of materials science and solid-state physics (condensed matter physics). The word crystallography is derived from the Ancient Greek word κρύσταλλος (krústallos; "clear ice, rock-crystal"), and γράφειν (gráphein; "to write"). In July 2012, the United Nations recognised the importance of the science of crystallography by proclaiming that 2014 would be the International Year of Crystallography.
Before the development of X-ray diffraction crystallography (see below), the study of crystals was based on physical measurements of their geometry using a goniometer. This involved measuring the angles of crystal faces relative to each other and to theoretical reference axes (crystallographic axes), and establishing the symmetry of the crystal in question. The position in 3D space of each crystal face is plotted on a stereographic net such as a Wulff net or Lambert net. The pole to each face is plotted on the net. Each point is labelled with its Miller index. The final plot allows the symmetry of the crystal to be established.
Crystallographic methods depend mainly on analysis of the diffraction patterns of a sample targeted by a beam of some type. X-rays are most commonly used; other beams used include electrons or neutrons. Crystallographers often explicitly state the type of beam used, as in the terms X-ray crystallography, neutron diffraction and electron diffraction. These three types of radiation interact with the specimen in different ways.- X-rays interact with the spatial distribution of electrons in the sample.
- Neutrons are scattered by the atomic nuclei through the strong nuclear forces, but in addition, the magnetic moment of neutrons is non-zero. They are therefore also scattered by magnetic fields. When neutrons are scattered from hydrogen-containing materials, they produce diffraction patterns with high noise levels. However, the material can sometimes be treated to substitute deuterium for hydrogen. Because of these different forms of interaction, the three types of radiation are suitable for different crystallographic studies.
- Electrons are charged particles and therefore interact with the total charge distribution of both the atomic nuclei and the electrons of the sample.
It is hard to focus x-rays or neutrons, but since electrons are charged they can be focused and are used in electron microscope to produce magnified images. There are many ways that transmission electron microscopy and related techniques such as scanning transmission electron microscopy, high-resolution electron microscopy can be used to obtain images with in many cases atomic resolution from which crystallographic information can be obtained. There are also other methods such as low-energy electron diffraction, low-energy electron microscopy and reflection high-energy electron diffraction which can be used to obtain crystallographic information about surfaces. (Full article...) -
Image 5
Malachite is a copper carbonate hydroxide mineral, with the formula Cu2CO3(OH)2. This opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses, in fractures and deep, underground spaces, where the water table and hydrothermal fluids provide the means for chemical precipitation. Individual crystals are rare, but occur as slender to acicular prisms. Pseudomorphs after more tabular or blocky azurite crystals also occur. (Full article...) -
Image 6
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 7
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 8
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 9
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 10
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 11
Apatite is a group of phosphate minerals, usually hydroxyapatite, fluorapatite and chlorapatite, with high concentrations of OH−, F− and Cl− ion, respectively, in the crystal. The formula of the admixture of the three most common endmembers is written as Ca10(PO4)6(OH,F,Cl)2, and the crystal unit cell formulae of the individual minerals are written as Ca10(PO4)6(OH)2, Ca10(PO4)6F2 and Ca10(PO4)6Cl2.
The mineral was named apatite by the German geologist Abraham Gottlob Werner in 1786, although the specific mineral he had described was reclassified as fluorapatite in 1860 by the German mineralogist Karl Friedrich August Rammelsberg. Apatite is often mistaken for other minerals. This tendency is reflected in the mineral's name, which is derived from the Greek word ἀπατάω (apatáō), which means to deceive. (Full article...) -
Image 12
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 13
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is, therefore, classified structurally as a framework silicate mineral and compositionally as an oxide mineral. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar.
Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation from α-quartz to β-quartz takes place abruptly at 573 °C (846 K; 1,063 °F). Since the transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold.
There are many different varieties of quartz, several of which are classified as gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Europe and Asia.
Quartz is the mineral defining the value of 7 on the Mohs scale of hardness, a qualitative scratch method for determining the hardness of a material to abrasion. (Full article...) -
Image 14
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...) -
Image 15
Zircon (/ˈzɜːrkɒn, -kən/) is a mineral belonging to the group of nesosilicates and is a source of the metal zirconium. Its chemical name is zirconium(IV) silicate, and its corresponding chemical formula is ZrSiO4. An empirical formula showing some of the range of substitution in zircon is (Zr1–y, REEy)(SiO4)1–x(OH)4x–y. Zircon precipitates from silicate melts and has relatively high concentrations of high field strength incompatible elements. For example, hafnium is almost always present in quantities ranging from 1 to 4%. The crystal structure of zircon is tetragonal crystal system. The natural color of zircon varies between colorless, yellow-golden, red, brown, blue, and green.
The name derives from the Persian zargun, meaning "gold-hued". This word is changed into "jargoon", a term applied to light-colored zircons. The English word "zircon" is derived from Zirkon, which is the German adaptation of this word. Yellow, orange, and red zircon is also known as "hyacinth", from the flower hyacinthus, whose name is of Ancient Greek origin. (Full article...) -
Image 16
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 17
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 18
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 19
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 20
Corundum is a crystalline form of aluminium oxide (Al2O3) typically containing traces of iron, titanium, vanadium, and chromium. It is a rock-forming mineral. It is a naturally transparent material, but can have different colors depending on the presence of transition metal impurities in its crystalline structure. Corundum has two primary gem varieties: ruby and sapphire. Rubies are red due to the presence of chromium, and sapphires exhibit a range of colors depending on what transition metal is present. A rare type of sapphire, padparadscha sapphire, is pink-orange.
The name "corundum" is derived from the Tamil-Dravidian word kurundam (ruby-sapphire) (appearing in Sanskrit as kuruvinda).
Because of corundum's hardness (pure corundum is defined to have 9.0 on the Mohs scale), it can scratch almost all other minerals. It is commonly used as an abrasive on sandpaper and on large tools used in machining metals, plastics, and wood. Emery, a variety of corundum with no value as a gemstone, is commonly used as an abrasive. It is a black granular form of corundum, in which the mineral is intimately mixed with magnetite, hematite, or hercynite.
In addition to its hardness, corundum has a density of 4.02 g/cm3 (251 lb/cu ft), which is unusually high for a transparent mineral composed of the low-atomic mass elements aluminium and oxygen. (Full article...) -
Image 21
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...) -
Image 22
Chalcopyrite (/ˌkælkəˈpaɪˌraɪt, -koʊ-/ KAL-kə-PY-ryte, -koh-) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green-tinged black.
On exposure to air, chalcopyrite tarnishes to a variety of oxides, hydroxides, and sulfates. Associated copper minerals include the sulfides bornite (Cu5FeS4), chalcocite (Cu2S), covellite (CuS), digenite (Cu9S5); carbonates such as malachite and azurite, and rarely oxides such as cuprite (Cu2O). It is rarely found in association with native copper. Chalcopyrite is a conductor of electricity.
Copper can be extracted from chalcopyrite ore using various methods. The two predominant methods are pyrometallurgy and hydrometallurgy, the former being the most commercially viable. (Full article...) -
Image 23
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 24
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 25
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...)
Selected mineralogist
-
Image 1Hatten Schuyler Yoder, Jr., (March 20, 1921 – August 2, 2003) was a geophysicist and experimental petrologist who conducted pioneering work on minerals under high pressure and temperature. He was noted for his study of silicates and igneous rocks. (Full article...)
-
Image 2
Karl Rössler (6 May 1788, in Wiesbaden – 23 August 1863, in Hanau) was a German manufacturer and mineralogist.
After a business apprenticeship in Frankfurt am Main, he acquired in 1818 a hat factory, which he transformed into a highly successful company. He had a keen interest in the geology, mineralogy and paleontology of the Wetterau, and accordingly, collected numerous minerals and fossils of the region. During his career, he worked closely with geologist Leopold von Buch. (Full article...) -
Image 3Rudolf Koechlin (11 November 1862 – 11 February 1939) was an Austrian mineralogist.
Koechlin was born and died in Vienna. He studied mineralogy, crystallography, petrology and geology at the University of Vienna, obtaining his doctorate in 1887 with a thesis on manganite, polianite and pyrolusite. At Vienna, his instructors included Gustav Tschermak and Albrecht Schrauf. In 1884 he began work as a volunteer in the mineralogical-petrography department of the Naturhistorisches Hofmuseum in Vienna. In 1897 he became a "custos-adjunct", later named a curator first-class (1912), and in 1920, was appointed director of the mineralogical-petrography department. (Full article...) -
Image 4Peggy-Kay Hamilton (1922–1959) was born in Illinois in 1922 and was an American Research Associate in Mineralogy in the Department of Geology at Columbia University. One of Hamilton's first research breakthroughs was developing Research Project 49, otherwise known as the study of clay minerals. In her later research years, her focus shifted and led to her becoming involved full time in the study of uranium.
Hamilton achieved success in the fields of geology and mineralogy; according to her frequent research partner and friend Paul F. Kerr, Hamilton was held in high regard by both students at Columbia University as well as professional colleagues at multiple scientific research institutions. (Full article...) -
Image 5Charles-Victor Mauguin (French: [ʃaʁl.vik.tɔʁ mo.gɛ̃]; 19 September 1878 – 25 April 1958), more often Charles Mauguin, was a French mineralogist and crystallographer. He and Carl Hermann invented an international standard notation for crystallographic groups called Hermann–Mauguin notation (also sometimes called international notation). (Full article...)
-
Image 6Hendrik Enno Boeke (12 September 1881, in Wormerveer – 6 December 1918, in Frankfurt am Main) was a Dutch mineralogist and petrographer.
From 1900 he studied chemistry and physics at the University of Amsterdam, where his instructors included Hendrik Willem Bakhuis Roozeboom and Johannes Diderik van der Waals. He then worked as an assistant under Gustav Tammann in Göttingen and to Friedrich Rinne at the Technical University of Hannover. In 1909 he became a lecturer of chemistry at the University of Königsberg, and during the following year, an associate professor of physical-chemical mineralogy and petrology at the University of Leipzig. (Full article...) -
Image 7
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...) -
Image 8Harald Bjørlykke (14 September 1901 – 28 February 1968) was a Norwegian geologist. (Full article...)
-
Image 9
Ernst Heinrich Oskar Kasimir Weinschenk (6 April 1865, Esslingen am Neckar – 26 March 1921, Munich) was a German mineralogist and petrologist.
He served as a professor at the "Technische Hochschule" in Munich (1897–1921) and at the University of Munich (from 1900). His scientific research included mineralogical analysis of meteorites, and studies of contact-metamorphic mineralization in the Alpine region of central Europe. He also conducted investigations on the origin of the sulfidic ore deposit at Silberberg in the Bavarian Forest, as well as the genesis of graphite deposits near Passau. Through the use of polarizing microscopy and thin sectioning, he determined numerous new minerals. (Full article...) -
Image 10Robert Minard Garrels (August 24, 1916 – March 8, 1988) was an American geochemist. Garrels applied experimental physical chemistry data and techniques to geology and geochemistry problems. The book Solutions, Minerals, and Equilibria co-authored in 1965 by Garrels and Charles L. Christ revolutionized aqueous geochemistry.
Garrels earned a bachelor's degree in geology from the University of Michigan in 1937. He went on to earn an M.S. degree from Northwestern University in 1939, his thesis work was on iron ores of Newfoundland in 1938. His Ph.D. was awarded in 1941 based on lab studies of complex formation between lead and chloride ions in aqueous solution. (Full article...) -
Image 11Joseph (Joe) Anthony Mandarino OC, FRSC (20 April 1929 in Chicago, Illinois – 19 September 2007) was an American-Canadian mineralogist and crystallographer. (Full article...)
-
Image 12
Alfred Wilhelm Stelzner (20 December 1840, Dresden – 25 February 1895, Wiesbaden) was a German geologist.
From 1859 to 1864 he was a student at the Bergakademie Freiberg, an institute where he later served as inspector. From 1871 to 1874 he was a professor of mineralogy and geology at the University of Córdoba in Argentina. In 1874 he returned to the Bergakademie at Freiberg, where he succeeded his former teacher, Bernhard von Cotta. Here, he taught classes until his death in 1895. (Full article...) -
Image 13Matthew Forster Heddle FRSE (28 April 1828 – 19 November 1897) was a Scottish physician and amateur mineralogist active through the 19th century. (Full article...)
-
Image 14
Thomas Thomson MD FRS FLS FRSE (12 April 1773 – 2 August 1852) was a Scottish chemist and mineralogist whose writings contributed to the early spread of Dalton's atomic theory. His scientific accomplishments include the invention of the saccharometer and he gave silicon its current name. He served as president of the Philosophical Society of Glasgow.
Thomson was the father of the botanist Thomas Thomson, and the uncle and father-in-law of the Medical Officer of Health Robert Thomson. (Full article...) -
Image 15Sarah Mawe (1767-1846) was an English mineralogist of the 19th century, appointed to serve Queen Victoria in that capacity from 1837 to 1840. (Full article...)
-
Image 16
Franz Ernst Neumann (11 September 1798 – 23 May 1895) was a German mineralogist and physicist. (Full article...) -
Image 17
Victor Mordechai Goldschmidt (10 February 1853 in Mainz – 8 May 1933 in Salzburg) was a German mineralogist, natural philosopher, and art collector. (Full article...) -
Image 18François Pierre Nicolas Gillet de Laumont (28 May 1747 – 1 June 1834) was a French mineralogist.
He was born in Paris, educated at a military school and served in the army from 1772 to 1784, when he was appointed inspector of mines. His attention in his leisure time was wholly given to mineralogy, and he assisted in organizing the new École des Mines in Paris. (Full article...) -
Image 19
Niels Steensen (Danish: Niels Steensen; Latinized to Nicolas Steno or Nicolaus Stenonius); 1 January 1638 – 25 November 1686 [NS: 11 January 1638 – 5 December 1686]) was a Danish scientist, a pioneer in both anatomy and geology who became a Catholic bishop in his later years.
Steensen was trained in the classical texts on science; however, by 1659 he seriously questioned accepted knowledge of the natural world. Importantly he questioned explanations for tear production, the idea that fossils grew in the ground and explanations of rock formation. His investigations and his subsequent conclusions on fossils and rock formation have led scholars to consider him one of the founders of modern stratigraphy and modern geology. The importance of Steensen's foundational contributions to geology may be gauged from the fact that half of the twenty papers in a recent miscellany volume on The Revolution in Geology from the Renaissance to the Enlightenment focus on Steensen, the "preeminent Baroque polymath and founder of modern geologic thought". (Full article...) -
Image 20Arthur Edmund Seaman (December 29, 1858 – July 10, 1937) was a professor at the Michigan College of Mines (now Michigan Technological University) and curator of the A. E. Seaman Mineral Museum which bears his name. (Full article...)
-
Image 21
Rodney Charles Ewing (born September 20, 1946) is an American mineralogist and materials scientist whose research is focused on the properties of nuclear materials.
He is the Frank Stanton Professor in Nuclear Security at the Center for International Security and Cooperation, a Senior Fellow of the Freeman Spogli Institute for International Studies, a Senior Fellow of the Precourt Institute for Energy, an Affiliate of the Stanford Woods Institute for the Environment, and a professor in the School of Earth, Energy and Environmental Sciences at Stanford University. (Full article...) -
Image 22
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...) -
Image 23
John Walker FRSE (1731–1803) was a Scottish minister and natural historian. He was Regius Professor of Natural history at the University of Edinburgh from 1779 to 1803. He was joint founder of the Royal Society of Edinburgh in 1783 and Moderator of the General Assembly of the Church of Scotland in 1790. (Full article...) -
Image 24
Paul Heinrich Ritter von Groth (23 June 1843 – 2 December 1927) was a German mineralogist. His most important contribution to science was his systematic classification of minerals based on their chemical compositions and crystal structures. (Full article...) -
Image 25
Count Lev Alekseyevich von Perovski (Russian: Лев Алексе́евич Перо́вский, also transliterated as Perofsky, Perovskii, Perovskiy, Perovsky, Perowski, and Perowsky; also credited as L.A. Perovski) (9 September 1792 – 21 November 1856) was a Russian nobleman and mineralogist who also served as Minister of Internal Affairs under Nicholas I of Russia.
In 1845, he proposed the creation of the Russian Geographical Society. (Full article...)
Related portals
Get involved
For editor resources and to collaborate with other editors on improving Wikipedia's Minerals-related articles, see WikiProject Rocks and minerals.
General images
-
Image 1Red cinnabar (HgS), a mercury ore, on dolomite. (from Mineral)
-
Image 4Gypsum desert rose (from Mineral)
-
Image 5Perfect basal cleavage as seen in biotite (black), and good cleavage seen in the matrix (pink orthoclase). (from Mineral)
-
Image 7When minerals react, the products will sometimes assume the shape of the reagent; the product mineral is termed a pseudomorph of (or after) the reagent. Illustrated here is a pseudomorph of kaolinite after orthoclase. Here, the pseudomorph preserved the Carlsbad twinning common in orthoclase. (from Mineral)
-
Image 8Asbestiform tremolite, part of the amphibole group in the inosilicate subclass (from Mineral)
-
Image 9Muscovite, a mineral species in the mica group, within the phyllosilicate subclass (from Mineral)
-
Image 12Diamond is the hardest natural material, and has a Mohs hardness of 10. (from Mineral)
-
Image 13Epidote often has a distinctive pistachio-green colour. (from Mineral)
-
Image 15Native gold. Rare specimen of stout crystals growing off of a central stalk, size 3.7 x 1.1 x 0.4 cm, from Venezuela. (from Mineral)
-
Image 18An example of elbaite, a species of tourmaline, with distinctive colour banding. (from Mineral)
-
Image 19Schist is a metamorphic rock characterized by an abundance of platy minerals. In this example, the rock has prominent sillimanite porphyroblasts as large as 3 cm (1.2 in). (from Mineral)
-
Image 20Mohs Scale versus Absolute Hardness (from Mineral)
-
Image 21Black andradite, an end-member of the orthosilicate garnet group. (from Mineral)
-
Image 23Mohs hardness kit, containing one specimen of each mineral on the ten-point hardness scale (from Mohs scale)
-
Image 24Sphalerite crystal partially encased in calcite from the Devonian Milwaukee Formation of Wisconsin (from Mineral)
-
Image 25Hübnerite, the manganese-rich end-member of the wolframite series, with minor quartz in the background (from Mineral)
-
Image 26Pink cubic halite (NaCl; halide class) crystals on a nahcolite matrix (NaHCO3; a carbonate, and mineral form of sodium bicarbonate, used as baking soda). (from Mineral)
Did you know ...?
- ... that diamond (example pictured) is superhard but not supertough?
- ... that the minerals armalcolite, pyroxferroite and tranquillityite were discovered in lunar rocks?
- ... that the third key of alchemist Basil Valentine may describe a complex chemical process known as the volatilization of gold chloride?
Subcategories
- Select [►] to view subcategories
Topics
Overview | ||
---|---|---|
Common minerals |
Ore minerals, mineral mixtures and ore deposits | |||||||||
---|---|---|---|---|---|---|---|---|---|
Ores |
| ||||||||
Deposit types |
Borates | |||||
---|---|---|---|---|---|
Carbonates | |||||
Oxides |
| ||||
Phosphates | |||||
Silicates | |||||
Sulfides | |||||
Other |
|
Crystalline | |||||||
---|---|---|---|---|---|---|---|
Cryptocrystalline | |||||||
Amorphous | |||||||
Miscellaneous | |||||||
Notable varieties |
|
Oxide minerals |
| ||||
---|---|---|---|---|---|
Silicate minerals | |||||
Other |
Gemmological classifications by E. Ya. Kievlenko (1980), updated | |||||||||
Jewelry stones |
| ||||||||
Jewelry-Industrial stones |
| ||||||||
Industrial stones |
| ||||||||
Mineral identification | |
---|---|
"Special cases" ("native elements and organic minerals") |
|
---|---|
"Sulfides and oxides" |
|
"Evaporites and similars" |
|
"Mineral structures with tetrahedral units" (sulfate anion, phosphate anion, silicon, etc.) |
|
Associated Wikimedia
The following Wikimedia Foundation sister projects provide more on this subject:
-
Commons
Free media repository -
Wikibooks
Free textbooks and manuals -
Wikidata
Free knowledge base -
Wikinews
Free-content news -
Wikiquote
Collection of quotations -
Wikisource
Free-content library -
Wikiversity
Free learning tools -
Wiktionary
Dictionary and thesaurus
References
-
Random portal
Purge server cache