Pyrite

Last updated
Pyrite
2780M-pyrite1.jpg
Pyrite cubic crystals on marl from Navajún, La Rioja, Spain (size: 95 by 78 millimetres (3.7 by 3.1 in), 512 grams (18.1 oz); main crystal: 31 millimetres (1.2 in) on edge)
General
Category Sulfide mineral
Formula
(repeating unit)
FeS2
Strunz classification 2.EB.05a
Dana classification2.12.1.1
Crystal system Isometric
Crystal class Diploidal (m3)
H-M symbol: (2/m 3)
Space group Pa3
Unit cell a = 5.417  Å, Z = 4
Identification
Formula mass 119.98 g/mol
ColorPale brass-yellow reflective; tarnishes darker and iridescent
Crystal habit Cubic, faces may be striated, but also frequently octahedral and pyritohedron. Often inter-grown, massive, radiated, granular, globular, and stalactitic.
Twinning Penetration and contact twinning
Cleavage Indistinct on {001}; partings on {011} and {111}
Fracture Very uneven, sometimes conchoidal
Tenacity Brittle
Mohs scale hardness6–6.5
Luster Metallic, glistening
Streak Greenish-black to brownish-black
Diaphaneity Opaque
Specific gravity 4.95–5.10
Density 4.8–5 g/cm3
Fusibility 2.5–3 to a magnetic globule
Solubility Insoluble in water
Other characteristics paramagnetic
References [1] [2] [3] [4]

The mineral pyrite (/ˈpaɪraɪt/) [5] , or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula FeS2 (iron(II) disulfide). Pyrite is considered the most common of the sulfide minerals.

Mineral Element or chemical compound that is normally crystalline and that has been formed as a result of geological processes

A mineral is, broadly speaking, a solid chemical compound that occurs naturally in pure form. A rock may consist of a single mineral, or may be an aggregate of two or more different minerals, spacially segregated into distinct phases. Compounds that occur only in living beings are usually excluded, but some minerals are often biogenic and/or are organic compounds in the sense of chemistry. Moreover, living beings often synthesize inorganic minerals that also occur in rocks.

Iron sulfide or Iron sulphide can refer to range of chemical compounds composed of iron and sulfur.

A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and plus (+) and minus (−) signs. These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a chemical name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulas can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than are chemical names and structural formulas.

Contents

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. [6] [7]

Hue Property of a color indicating balance of color perceived by the normal human eye

Hue is one of the main properties of a color, defined technically, as "the degree to which a stimulus can be described as similar to or different from stimuli that are described as red, green, blue, and yellow",. Hue can typically be represented quantitatively by a single number, often corresponding to an angular position around a central or neutral point or axis on a colorspace coordinate diagram or color wheel, or by its dominant wavelength or that of its complementary color. The other color appearance parameters are colorfulness, saturation, lightness, and brightness.

Gold Chemical element with atomic number 79

Gold is a chemical element with symbol Au and atomic number 79, making it one of the higher atomic number elements that occur naturally. In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions. Gold often occurs in free elemental (native) form, as nuggets or grains, in rocks, in veins, and in alluvial deposits. It occurs in a solid solution series with the native element silver and also naturally alloyed with copper and palladium. Less commonly, it occurs in minerals as gold compounds, often with tellurium.

Coal A combustible sedimentary rock composed primarily of carbon

Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements; chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed if dead plant matter decays into peat and over millions of years the heat and pressure of deep burial converts the peat into coal.

The name pyrite is derived from the Greek πυρίτης (pyritēs), "of fire" or "in fire", [8] in turn from πύρ (pyr), "fire". [9] 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 we now call pyrite. [10]

Greek language language spoken in Greece, Cyprus and Southern Albania

Greek is an independent branch of the Indo-European family of languages, native to Greece, Cyprus and other parts of the Eastern Mediterranean and the Black Sea. It has the longest documented history of any living Indo-European language, spanning more than 3000 years of written records. Its writing system has been the Greek alphabet for the major part of its history; other systems, such as Linear B and the Cypriot syllabary, were used previously. The alphabet arose from the Phoenician script and was in turn the basis of the Latin, Cyrillic, Armenian, Coptic, Gothic, and many other writing systems.

Steel alloy made by combining iron and other elements

Steel is an alloy of iron and carbon, and sometimes other elements. Because of its high tensile strength and low cost, it is a major component used in buildings, infrastructure, tools, ships, automobiles, machines, appliances, and weapons.

Pliny the Elder Roman military commander and writer

Pliny the Elder was a Roman author, naturalist and natural philosopher, a naval and army commander of the early Roman Empire, and friend of emperor Vespasian.

By Georgius Agricola's time, c. 1550, the term had become a generic term for all of the sulfide minerals. [11]

Georgius Agricola German mineralogist

Georgius Agricola was a German mineralogist and metallurgist. He is known as "the father of mineralogy", he was born at Glauchau in Saxony. His birth name was Georg Pawer ; Agricola is the Latinized version of his name, by which he was known his entire adult life; Georgius and Georg, Agricola and Bauer all mean "farmer" in their respective languages. He is best known for his book De Re Metallica (1556).

The pyrite group of minerals is a set of cubic crystal system minerals with diploidal structure. Each metallic element is bonded to six "dumbbell" pairs of non-metallic elements and each "dumbbell" pair is bonded to six metal atoms.

Pyrite under normal and polarized light Pyrite under Normal and Polarized light.jpg
Pyrite under normal and polarized light

Pyrite is usually found associated with other sulfides or oxides in quartz veins, sedimentary rock, and metamorphic rock, as well as in coal beds and as a replacement mineral in fossils, but has also been identified in the sclerites of scaly-foot gastropods. [12] Despite being nicknamed fool's gold, pyrite is sometimes found in association with small quantities of gold. Gold and arsenic occur as a coupled substitution in the pyrite structure. In the Carlin–type gold deposits, arsenian pyrite contains up to 0.37% gold by weight. [13]

Quartz mineral composed of silicon and oxygen atoms 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 a mineral composed of silicon and oxygen atoms 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 the second most abundant mineral in Earth's continental crust, behind feldspar.

Vein (geology) sheetlike body within a rock

In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Veins form when mineral constituents carried by an aqueous solution within the rock mass are deposited through precipitation. The hydraulic flow involved is usually due to hydrothermal circulation.

Sedimentary rock Rock formed by the deposition and subsequent cementation of material

Sedimentary rocks are types of rock that are formed by the deposition and subsequent cementation of mineral or organic particles on the floor of oceans or other bodies of water at the Earth's surface. Sedimentation is the collective name for processes that cause these particles to settle in place. The particles that form a sedimentary rock are called sediment, and may be composed of geological detritus (minerals) or biological detritus. Before being deposited, the geological detritus was formed by weathering and erosion from the source area, and then transported to the place of deposition by water, wind, ice, mass movement or glaciers, which are called agents of denudation. Biological detritus was formed by bodies and parts of dead aquatic organisms, as well as their fecal mass, suspended in water and slowly piling up on the floor of water bodies. Sedimentation may also occur as dissolved minerals precipitate from water solution.

Uses

An abandoned pyrite mine near Pernek in Slovakia. Stolna pri Perneku.jpg
An abandoned pyrite mine near Pernek in Slovakia.

Pyrite enjoyed brief popularity in the 16th and 17th centuries as a source of ignition in early firearms, most notably the wheellock, where a sample of pyrite was placed against a circular file to strike the sparks needed to fire the gun.[ citation needed ]

Combustion high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized in a mixture termed as smoke

Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combustion in a fire produces a flame, and the heat produced can make combustion self-sustaining. Combustion is often a complicated sequence of elementary radical reactions. Solid fuels, such as wood and coal, first undergo endothermic pyrolysis to produce gaseous fuels whose combustion then supplies the heat required to produce more of them. Combustion is often hot enough that incandescent light in the form of either glowing or a flame is produced. A simple example can be seen in the combustion of hydrogen and oxygen into water vapor, a reaction commonly used to fuel rocket engines. This reaction releases 242 kJ/mol of heat and reduces the enthalpy accordingly :

Firearm weapon that launches a projectile at high velocity through the confined burning of a propellant

A firearm is a portable gun that inflicts damage on targets by launching one or more projectiles driven by rapidly expanding high-pressure gas produced chemically by exothermic combustion (deflagration) of propellant within an ammunition cartridge. If gas pressurization is achieved through mechanical gas compression rather than through chemical propellant combustion, then the gun is technically an air gun, not a firearm.

Wheellock firearm action

A wheellock, wheel-lock or wheel lock, is a friction-wheel mechanism to cause a spark for firing a firearm. It was the next major development in firearms technology after the matchlock and the first self-igniting firearm. Its name is from its rotating steel wheel to provide ignition. Developed in Europe around 1500, it was used alongside the matchlock and was later superseded by the snaplock (1540s), the snaphance (1560s) and the flintlock.

Pyrite has been used since classical times to manufacture copperas (iron(II) sulfate). Iron pyrite was heaped up and allowed to weather (an example of an early form of heap leaching). The acidic runoff from the heap was then boiled with iron to produce iron sulfate. In the 15th century, new methods of such leaching began to replace the burning of sulfur as a source of sulfuric acid. By the 19th century, it had become the dominant method. [14]

Pyrite remains in commercial use for the production of sulfur dioxide, for use in such applications as the paper industry, and in the manufacture of sulfuric acid. Thermal decomposition of pyrite into FeS (iron(II) sulfide) and elemental sulfur starts at 540 °C (1,004 °F); at around 700 °C (1,292 °F), pS2 is about 1 atm. [15]

A newer commercial use for pyrite is as the cathode material in Energizer brand non-rechargeable lithium batteries. [16]

Pyrite is a semiconductor material with a band gap of 0.95 eV. [17] Pure pyrite is naturally n-type, in both crystal and thin-film forms, potentially due to sulfur vacancies in the pyrite crystal structure acting as n-dopants [18] .

During the early years of the 20th century, pyrite was used as a mineral detector in radio receivers, and is still used by crystal radio hobbyists. Until the vacuum tube matured, the crystal detector was the most sensitive and dependable detector available – with considerable variation between mineral types and even individual samples within a particular type of mineral. Pyrite detectors occupied a midway point between galena detectors and the more mechanically complicated perikon mineral pairs. Pyrite detectors can be as sensitive as a modern 1N34A germanium diode detector. [19] [20]

Pyrite has been proposed as an abundant, non-toxic, inexpensive material in low-cost photovoltaic solar panels. [21] Synthetic iron sulfide was used with copper sulfide to create the photovoltaic material. [22] . More recent efforts are working toward thin-film solar cells made entirely of pyrite. [23]

Pyrite is used to make marcasite jewelry. Marcasite jewelry, made from small faceted pieces of pyrite, often set in silver, was known since ancient times and was popular in the Victorian era. [24] At the time when the term became common in jewelry making, "marcasite" referred to all iron sulfides including pyrite, and not to the orthorhombic FeS2 mineral marcasite which is lighter in color, brittle and chemically unstable, and thus not suitable for jewelry making. Marcasite jewelry does not actually contain the mineral marcasite.

China represents the main importing country with an import of around 376,000 tonnes, which resulted at 45% of total global imports. China is also the fastest growing in terms of the unroasted iron pyrites imports, with a CAGR of +27.8% from 2007 to 2016. In value terms, China ($47M) constitutes the largest market for imported unroasted iron pyrites worldwide, making up 65% of global imports. [25]

Formal oxidation states for pyrite, marcasite, and arsenopyrite

From the perspective of classical inorganic chemistry, which assigns formal oxidation states to each atom, pyrite is probably best described as Fe2+S22−. This formalism recognizes that the sulfur atoms in pyrite occur in pairs with clear S–S bonds. These persulfide units can be viewed as derived from hydrogen disulfide, H2S2. Thus pyrite would be more descriptively called iron persulfide, not iron disulfide. In contrast, molybdenite, MoS2, features isolated sulfide (S2−) centers and the oxidation state of molybdenum is Mo4+. The mineral arsenopyrite has the formula FeAsS. Whereas pyrite has S2 subunits, arsenopyrite has [AsS] units, formally derived from deprotonation of H2AsSH. Analysis of classical oxidation states would recommend the description of arsenopyrite as Fe3+[AsS]3−. [26]

Crystallography

Crystal structure of pyrite. In the center of the cell a S2 pair is seen in yellow. FeS2structure.png
Crystal structure of pyrite. In the center of the cell a S2 pair is seen in yellow.

Iron-pyrite FeS2 represents the prototype compound of the crystallographic pyrite structure. The structure is simple cubic and was among the first crystal structures solved by X-ray diffraction. [27] It belongs to the crystallographic space group Pa3 and is denoted by the Strukturbericht notation C2. Under thermodynamic standard conditions the lattice constant of stoichiometric iron pyrite FeS2 amounts to 541.87 pm. [28] The unit cell is composed of a Fe face-centered cubic sublattice into which the S ions are embedded. The pyrite structure is also used by other compounds MX2 of transition metals M and chalcogens X = O, S, Se and Te. Also certain dipnictides with X standing for P, As and Sb etc. are known to adopt the pyrite structure. [29]

In the first bonding sphere, the Fe atoms are surrounded by six S nearest neighbours, in a distorted octahedral arrangement. The material is a diamagnetic semiconductor and the Fe ions should be considered to be in a low spin divalent state (as shown by Mössbauer spectroscopy as well as XPS), rather than a tetravalent state as the stoichiometry would suggest.

The positions of X ions in the pyrite structure may be derived from the fluorite structure, starting from a hypothetical Fe2+(S)2 structure. Whereas F ions in CaF2 occupy the centre positions of the eight subcubes of the cubic unit cell (141414) etc., the S ions in FeS2 are shifted from these high symmetry positions along <111> axes to reside on (uuu) and symmetry-equivalent positions. Here, the parameter u should be regarded as a free atomic parameter that takes different values in different pyrite-structure compounds (iron pyrite FeS2: u(S) = 0.385 [30] ). The shift from fluorite u = 0.25 to pyrite u = 0.385 is rather large and creates a S-S distance that is clearly a binding one. This is not surprising as in contrast to F an ion S is not a closed shell species. It is isoelectronic with a chlorine atom, also undergoing pairing to form Cl2 molecules. Both low spin Fe2+ and the disulfide S22− moeties are closed shell entities, explaining the diamagnetic and semiconducting properties.

The S atoms have bonds with three Fe and one other S atom. The site symmetry at Fe and S positions is accounted for by point symmetry groups C3i and C3, respectively. The missing center of inversion at S lattice sites has important consequences for the crystallographic and physical properties of iron pyrite. These consequences derive from the crystal electric field active at the sulfur lattice site, which causes a polarisation of S ions in the pyrite lattice. [31] The polarisation can be calculated on the basis of higher-order Madelung constants and has to be included in the calculation of the lattice energy by using a generalised Born–Haber cycle. This reflects the fact that the covalent bond in the sulfur pair is inadequately accounted for by a strictly ionic treatment.

Arsenopyrite has a related structure with heteroatomic As-S pairs rather than homoatomic ones. Marcasite also possesses homoatomic anion pairs, but the arrangement of the metal and diatomic anions is different from that of pyrite. Despite its name a chalcopyrite does not contain dianion pairs, but single S2− sulfide anions.

Crystal habit

Dodecahedron- shaped crystals from Italy. Pyrite elbe.jpg
Dodecahedron- shaped crystals from Italy.

Pyrite usually forms cuboid crystals, sometimes forming in close association to form raspberry-shaped masses called framboids. However, under certain circumstances, it can form anastamozing filaments or T-shaped crystals. [32] Pyrite can also form almost perfect dodecahedral shapes known as pyritohedra and this suggests an explanation for the artificial geometrical models found in Europe as early as the 5th century BC. [33]

Varieties

Cattierite (Co S 2) and vaesite (Ni S 2) are similar in their structure and belong also to the pyrite group.

Bravoite is a nickel-cobalt bearing variety of pyrite, with > 50% substitution of Ni 2+ for Fe2+ within pyrite. Bravoite is not a formally recognised mineral, and is named after Peruvian scientist Jose J. Bravo (1874–1928). [34]

Distinguishing similar minerals

It is distinguishable from native gold by its hardness, brittleness and crystal form. Natural gold tends to be anhedral (irregularly shaped), whereas pyrite comes as either cubes or multifaceted crystals. Pyrite can often be distinguished by the striations which, in many cases, can be seen on its surface. Chalcopyrite is brighter yellow with a greenish hue when wet and is softer (3.5–4 on Mohs' scale). [35] Arsenopyrite is silver white and does not become more yellow when wet.

Hazards

A pyrite cube (center) has dissolved away from a host rock, leaving behind trace gold. GoldinPyriteDrainage acide.JPG
A pyrite cube (center) has dissolved away from a host rock, leaving behind trace gold.

Iron pyrite is unstable at Earth's surface: iron pyrite exposed to air and water decomposes into iron oxides and sulfate. This process is hastened by the action of Acidithiobacillus bacteria which oxidize the pyrite to produce ferrous iron and sulfate. These reactions occur more rapidly when the pyrite is in fine crystals and dust, which is the form it takes in most mining operations.

Acid drainage

Sulfate released from decomposing pyrite combines with water, producing sulfuric acid, leading to acid rock drainage. An example of acid rock drainage caused by pyrite is the 2015 Gold King Mine waste water spill.

Dust explosions

Pyrite oxidation is sufficiently exothermic that underground coal mines in high-sulfur coal seams have occasionally had serious problems with spontaneous combustion in the mined-out areas of the mine. The solution is to hermetically seal the mined-out areas to exclude oxygen.[ citation needed ]

In modern coal mines, limestone dust is sprayed onto the exposed coal surfaces to reduce the hazard of dust explosions. This has the secondary benefit of neutralizing the acid released by pyrite oxidation and therefore slowing the oxidation cycle described above, thus reducing the likelihood of spontaneous combustion. In the long term, however, oxidation continues, and the hydrated sulfates formed may exert crystallization pressure that can expand cracks in the rock and lead eventually to roof fall. [36]

Weakened building materials

Building stone containing pyrite tends to stain brown as the pyrite oxidizes. This problem appears to be significantly worse if any marcasite is present. [37] The presence of pyrite in the aggregate used to make concrete can lead to severe deterioration as the pyrite oxidizes. [38] In early 2009, problems with Chinese drywall imported into the United States after Hurricane Katrina were attributed to oxidation of pyrite, which releases hydrogen sulfide gas. These problems included a foul odor and corrosion of copper wiring. [39] In the United States, in Canada, [40] and more recently in Ireland, [41] [42] [43] where it was used as underfloor infill, pyrite contamination has caused major structural damage. Modern tests for aggregate materials [44] certify such materials as free of pyrite.

Pyritised fossils

Pyrite and marcasite commonly occur as replacement pseudomorphs after fossils in black shale and other sedimentary rocks formed under reducing environmental conditions. [45] However, pyrite dollars or pyrite suns which have an appearance similar to sand dollars are pseudofossils and lack the pentagonal symmetry of the animal.

Images

Related Research Articles

Bioleaching is the extraction of metals from their ores through the use of living organisms. This is much cleaner than the traditional heap leaching using cyanide. Bioleaching is one of several applications within biohydrometallurgy and several methods are used to recover copper, zinc, lead, arsenic, antimony, nickel, molybdenum, gold, silver, and cobalt.

Arsenopyrite sulfide mineral

Arsenopyrite is an iron arsenic sulfide (FeAsS). It is a hard metallic, opaque, steel grey to silver white mineral with a relatively high specific gravity of 6.1. When dissolved in nitric acid, it releases elemental sulfur. When arsenopyrite is heated, it produces poisonous sulfur and arsenic fumes which can be fatal if inhaled in large quantities. With 46% arsenic content, arsenopyrite, along with orpiment, is a principal ore of arsenic. When deposits of arsenopyrite become exposed to the atmosphere, the mineral will slowly oxidize, converting the arsenopyrite into an iron arsenate, a relatively stable compound. Arsenopyrite is generally an acid consuming sulfide mineral unlike iron pyrite which can lead to acid mine drainage.

Chalcopyrite sulfide mineral

Chalcopyrite ( KAL-ko-PY-ryt) is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical formula CuFeS2. 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.

Sulfide salt or other derivative of hydrogen sulfide or organic compound having the structure RSR (R ≠ H)

Sulfide (British English sulphide) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions. Solutions of sulfide salts are corrosive. Sulfide also refers to chemical compounds large families of inorganic and organic compounds, e.g. lead sulfide and dimethyl sulfide. Hydrogen sulfide (H2S) and bisulfide (SH-) are the conjugate acids of sulfide.

Melanterite sulfate mineral

Melanterite is a mineral form of hydrous iron(II) sulfate: FeSO4·7H2O. It is the iron analogue of the copper sulfate chalcanthite. It alters to siderotil by loss of water. It is a secondary sulfate mineral which forms from the oxidation of primary sulfide minerals such as pyrite and marcasite in the near-surface environment. It often occurs as a post mine encrustation on old underground mine surfaces. It also occurs in coal and lignite seams exposed to humid air and as a rare sublimate phase around volcanic fumaroles. Associated minerals include pisanite, chalcanthite, epsomite, pickeringite, halotrichite and other sulfate minerals.

Covellite sulfide mineral

Covellite is a rare copper sulfide mineral with the formula CuS. This indigo blue mineral is ubiquitous in copper ores, it is found in limited abundance and is not an important ore of copper itself, although it is well known to mineral collectors.

Pyrrhotite sulfide mineral; polytypes: 11H, 3T, 4C, 4H, 4M, 5C, 6C, 6M, 7H

Pyrrhotite is an iron sulfide mineral with the formula Fe(1-x)S. It is a nonstoichiometric variant of FeS, the mineral known as troilite. Pyrrhotite is also called magnetic pyrite, because the color is similar to pyrite and it is weakly magnetic. The magnetism decreases as the iron content increases, and troilite is non-magnetic.

Marcasite sulfide mineral

The mineral marcasite, sometimes called white iron pyrite, is iron sulfide (FeS2) with orthorhombic crystal structure. It is physically and crystallographically distinct from pyrite, which is iron sulfide with cubic crystal structure. Both structures do have in common that they contain the disulfide S22− ion having a short bonding distance between the sulfur atoms. The structures differ in how these di-anions are arranged around the Fe2+ cations. Marcasite is lighter and more brittle than pyrite. Specimens of marcasite often crumble and break up due to the unstable crystal structure.

Wurtzite sulfide mineral; polytypes: 2H, 4H, 6H, 10H, 15R

Wurtzite is a zinc iron sulfide mineral ( S) a less frequently encountered mineral form of sphalerite. The iron content is variable up to eight percent. It is trimorphous with matraite and sphalerite.

Chalcogenide

A chalcogenide is a chemical compound consisting of at least one chalcogen anion and at least one more electropositive element. Although all group 16 elements of the periodic table are defined as chalcogens, the term chalcogenide is more commonly reserved for sulfides, selenides, tellurides, and polonides, rather than oxides. Many metal ores exist as chalcogenides. Photoconductive chalcogenide glasses are used in xerography. Some pigments and catalysts are also based on chalcogenides. The metal dichalcogenide MoS2 is a common solid lubricant.

Copiapite sulfate mineral

Copiapite is a hydrated iron sulfate mineral with formula: Fe2+Fe3+4(SO4)6(OH)2·20(H2O). Copiapite can also refer to a mineral group, the copiapite group.

Greigite iron sulfide mineral of spinel structure

Greigite is an iron sulfide mineral with formula Fe3S4 (Iron(II,III) sulfide). It is the sulfur equivalent of the iron oxide magnetite (Fe3O4). It was first described in 1964 for an occurrence in San Bernardino County, California, and named after the mineralogist and physical chemist Joseph W. Greig (1895–1977).

Mineral redox buffer

In geology, a redox buffer is an assemblage of minerals or compounds that constrains oxygen fugacity as a function of temperature. Knowledge of the redox conditions (or equivalently, oxygen fugacities) at which a rock forms and evolves can be important for interpreting the rock history. Iron, sulfur, and manganese are three of the relatively abundant elements in the Earth's crust that occur in more than one oxidation state. For instance, iron, the fourth most abundant element in the crust, exists as native iron, ferrous iron (Fe2+), and ferric iron (Fe3+). The redox state of a rock affects the relative proportions of the oxidation states of these elements and hence may determine both the minerals present and their compositions. If a rock contains pure minerals that constitute a redox buffer, then the oxygen fugacity of equilibration is defined by one of the curves in the accompanying fugacity-temperature diagram.

Biomining

Biomining is a technique of extracting metals from ores and other solid materials typically using prokaryotes or fungi. These organisms secrete different organic compounds that chelate metals from the environment and bring it back to the cell where they are typically used to coordinate electrons. It was discovered in the mid 1900s that microorganisms use metals in the cell. Some microbes can use stable metals such as iron, copper, zinc, and gold as well as unstable atoms such as uranium and thorium. Companies can now grow large chemostats of microbes that are leaching metals from their media, these vats of culture can then be transformed into many marketable metal compounds. Biomining is an environmentally friendly technique compared to typical mining. Mining releases many pollutants while the only chemicals released from biomining is any metabolites or gasses that the bacteria secrete. The same concept can be used for bioremediation models. Bacteria can be inoculated into environments contaminated with metals, oils, or other toxic compounds. The bacteria can clean the environment by absorbing these toxic compounds to create energy in the cell. Microbes can achieve things at a chemical level that could never be done by humans. Bacteria can mine for metals, clean oil spills, purify gold, and use radioactive elements for energy.

Mackinawite sulfide mineral

Mackinawite is an iron nickel sulfide mineral with formula (Fe,Ni)1 + xS. The mineral crystallizes in the tetragonal crystal system and has been described as a distorted, close packed, cubic array of S atoms with some of the gaps filled with Fe. Mackinawite occurs as opaque bronze to grey-white tabular crystals and anhedral masses. It has a Mohs hardness of 2.5 and a specific gravity of 4.17. It was first described in 1962 for an occurrence in the Mackinaw mine, Snohomish County, Washington for which it was named.

Iron(III) sulfate chemical compound

Iron(III) sulfate (or ferric sulfate), is the chemical compound with the formula Fe2(SO4)3. Usually yellow, it is a salt and soluble in water. A variety of hydrates are also known. Solutions are used in dyeing as a mordant, and as a coagulant for industrial wastes. It is also used in pigments, and in pickling baths for aluminum and steel.

Copper sulfides describe a family of chemical compounds and minerals with the formula CuSy. Both minerals and synthetic materials comprise these compounds. Some copper sulfides are economically important ores.

Rozenite is a hydrous iron sulfate mineral, Fe2+SO4•4(H2O).

The sulfarsenide minerals are a subgroup of the sulfide minerals which include arsenic replacing sulfur as an anion in the formula. Antimony and bismuth may occur with or in place of the arsenic as in ullmannite. The chemical formula of a sulfarsenide looks like a sulfosalt, however the structures are distinctly different. In sulfosalts the arsenic replaces a metal ion.

Pressure Oxidation is a process for extracting gold from refractory ore.

References

  1. Hurlbut, Cornelius S.; Klein, Cornelis (1985). Manual of Mineralogy (20th ed.). New York, NY: John Wiley and Sons. pp. 285–286. ISBN   978-0-471-80580-9.
  2. "Pyrite". Webmineral.com. Retrieved 2011-05-25.
  3. "Pyrite". Mindat.org. Retrieved 2011-05-25.
  4. Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C., eds. (1990). "Pyrite" (PDF). Handbook of Mineralogy. Volume I (Elements, Sulfides, Sulfosalts). Chantilly, VA, US: Mineralogical Society of America. ISBN   978-0962209734.
  5. https://dictionary.cambridge.org/dictionary/english/pyrite
  6. Jackson, Julia A.; Mehl, James; Neuendorf, Klaus (2005). Glossary of Geology. American Geological Institute. p. 82. ISBN   9780922152766 via Google Books.
  7. Fay, Albert H. (1920). A Glossary of the Mining and Mineral Industry. United States Bureau of Mines. pp. 103–104 via Google Books.
  8. Henry George Liddell; Robert Scott (eds.). "πυρίτης". A Greek-English Lexicon. Tufts University via Perseus.
  9. Henry George Liddell; Robert Scott (eds.). "πύρ". A Greek-English Lexicon. Tufts University via Perseus.
  10. Dana, James Dwight; Dana, Edward Salisbury (1911). Descriptive Mineralogy (6th ed.). New York: Wiley. p. 86.
  11. "De re metallica". The Mining Magazine. Translated by Hoover, H.C.; Hoover, L.H. London: Dover. 1950 [1912]. see footnote on p. 112.
  12. "Armor-plated snail discovered in deep sea". news.nationalgeographic.com. Washington, DC: National Geographic Society. Retrieved 2016-08-29.
  13. Fleet, M. E.; Mumin, A. Hamid (1997). "Gold-bearing arsenian pyrite and marcasite and arsenopyrite from Carlin Trend gold deposits and laboratory synthesis" (PDF). American Mineralogist. 82: 182–193.
  14. "Industrial England in the Middle of the Eighteenth Century". Nature. 83 (2113): 264–268. 1910-04-28. Bibcode:1910Natur..83..264.. doi:10.1038/083264a0.
  15. Rosenqvist, Terkel (2004). Principles of extractive metallurgy (2nd ed.). Tapir Academic Press. p. 52. ISBN   978-82-519-1922-7.
  16. "Cylindrical Primary Lithium [battery]". Lithium-Iron Disulfide (Li-FeS2) (PDF). Handbook and Application Manual. Energizer Corporation. 2017-09-19. Retrieved 2018-04-20.
  17. Ellmer, K. & Tributsch, H. (2000-03-11). "Iron Disulfide (Pyrite) as Photovoltaic Material: Problems and Opportunities". Proceedings of the 12th Workshop on Quantum Solar Energy Conversion – (QUANTSOL 2000). Archived from the original on 2010-01-15.
  18. Xin Zhang & Mengquin Li (2017-06-19). "Potential resolution to the doping puzzle in iron pyrite: Carrier type determination by Hall effect and thermopower". Physical Review Materials. Archived from the original on 2017-06-19.
  19. The Principles Underlying Radio Communication. U.S. Army Signal Corps. Radio Pamphlet. 40. 1918. section 179, pp. 302–305 via Google Books.
  20. Thomas H. Lee (2004). The Design of Radio Frequency Integrated Circuits (2nd ed.). Cambridge, UK: Cambridge University Press. pp. 4–6. ISBN   9780521835398 via Google Books.
  21. Wadia, Cyrus; Alivisatos, A. Paul; Kammen, Daniel M. (2009). "Materials availability expands the opportunity for large-scale photovoltaics deployment". Environmental Science & Technology. 43 (6): 2072–7. Bibcode:2009EnST...43.2072W. doi:10.1021/es8019534. PMID   19368216.
  22. Sanders, Robert (17 February 2009). "Cheaper materials could be key to low-cost solar cells". Berkeley, CA: University of California – Berkeley.
  23. Xin Zhang & Mengquin Li (2017-06-19). "Potential resolution to the doping puzzle in iron pyrite: Carrier type determination by Hall effect and thermopower". Physical Review Materials. Archived from the original on 2017-06-19.
  24. Hesse, Rayner W. (2007). Jewelrymaking Through History: An Encyclopedia. Greenwood Publishing Group. p. 15. ISBN   978-0-313-33507-5.
  25. "Which Country Imports the Most Unroasted Iron Pyrites in the World? – IndexBox". www.indexbox.io. Retrieved 2018-09-11.
  26. Vaughan, D. J.; Craig, J. R. (1978). Mineral Chemistry of Metal Sulfides. Cambridge, UK: Cambridge University Press. ISBN   978-0-521-21489-6.
  27. Bragg, W. L. (1913). "The structure of some crystals as indicated by their diffraction of X-rays". Proceedings of the Royal Society A . 89 (610): 248–277. Bibcode:1913RSPSA..89..248B. doi:10.1098/rspa.1913.0083. JSTOR   93488.
  28. Birkholz, M.; Fiechter, S.; Hartmann, A.; Tributsch, H. (1991). "Sulfur deficiency in iron pyrite (FeS2−x) and its consequences for band structure models". Physical Review B. 43 (14): 11926–11936. Bibcode:1991PhRvB..4311926B. doi:10.1103/PhysRevB.43.11926.
  29. Brese, Nathaniel E.; von Schnering, Hans Georg (1994). "Bonding Trends in Pyrites and a Reinvestigation of the Structure of PdAs2, PdSb2, PtSb2 and PtBi2". Z. Anorg. Allg. Chem. 620 (3): 393–404. doi:10.1002/zaac.19946200302.
  30. Stevens, E. D.; Delucia, M. L.; Coppens, P. (1980). "Experimental observation of the Effect of Crystal Field Splitting on the Electron Density Distribution of Iron Pyrite". Inorg. Chem. 19 (4): 813–820. doi:10.1021/ic50206a006.
  31. Birkholz, M. (1992). "The crystal energy of pyrite". J. Phys.: Condens. Matter. 4 (29): 6227–6240. Bibcode:1992JPCM....4.6227B. doi:10.1088/0953-8984/4/29/007.
  32. Bonev, I. K.; Garcia-Ruiz, J. M.; Atanassova, R.; Otalora, F.; Petrussenko, S. (2005). "Genesis of filamentary pyrite associated with calcite crystals". European Journal of Mineralogy. 17 (6): 905–913. Bibcode:2005EJMin..17..905B. CiteSeerX   10.1.1.378.3304 . doi:10.1127/0935-1221/2005/0017-0905.
  33. The pyritohedral form is described as a dodecahedron with pyritohedral symmetry; Dana J. et al., (1944), System of mineralogy, New York, p 282
  34. Mindat – bravoite. Mindat.org (2011-05-18). Retrieved on 2011-05-25.
  35. Pyrite on. Minerals.net (2011-02-23). Retrieved on 2011-05-25.
  36. Zodrow, E (2005). "Colliery and surface hazards through coal-pyrite oxidation (Pennsylvanian Sydney Coalfield, Nova Scotia, Canada)". International Journal of Coal Geology. 64: 145–155. doi:10.1016/j.coal.2005.03.013.
  37. Bowles, Oliver (1918) The Structural and Ornamental Stones of Minnesota. Bulletin 663, United States Geological Survey, Washington. p. 25.
  38. Tagnithamou, A; Sariccoric, M; Rivard, P (2005). "Internal deterioration of concrete by the oxidation of pyrrhotitic aggregates". Cement and Concrete Research. 35: 99–107. doi:10.1016/j.cemconres.2004.06.030.
  39. Angelo, William (28 January 2009) A Material Odor Mystery Over Foul-Smelling Drywall. Engineering News-Record.
  40. "PYRITE and Your House, What Home-Owners Should Know Archived 2012-01-06 at the Wayback Machine " – ISBN   2-922677-01-X – Legal deposit – National Library of Canada, May 2000
  41. Shrimer, F. and Bromley, AV (2012) "Pyritic Heave in Ireland". Proceedings of the Euroseminar on Building Materials. International Cement Microscopy Association (Halle Germany)
  42. Homeowners in protest over pyrite damage to houses. The Irish Times (11 June 2011
  43. Brennan, Michael (22 February 2010) Devastating 'pyrite epidemic' hits 20,000 newly built houses. Irish Independent
  44. I.S. EN 13242:2002 Aggregates for unbound and hydraulically bound materials for use in civil engineering work and road construction
  45. Briggs, D. E. G.; Raiswell, R.; Bottrell, S. H.; Hatfield, D.; Bartels, C. (1996-06-01). "Controls on the pyritization of exceptionally preserved fossils; an analysis of the Lower Devonian Hunsrueck Slate of Germany". American Journal of Science. 296 (6): 633–663. Bibcode:1996AmJS..296..633B. doi:10.2475/ajs.296.6.633. ISSN   0002-9599.

Further reading