Alabandite
Encyclopedia
Alabandite or alabandine is a a rarely occurring manganese
Manganese
Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...

 sulfide mineral
Sulfide mineral
The sulfide minerals are a class of minerals containing sulfide as the major anion. Some sulfide minerals are economically important as metal ores. The sulfide class also includes the selenides, the tellurides, the arsenides, the antimonides, the bismuthinides, the sulfarsenides and the sulfosalts...

. It crystallizes in the cubic crystal system
Cubic crystal system
In crystallography, the cubic 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....

 with the chemical composition Mn
Manganese
Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...

2+S
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...

 and develops commonly massive to granular aggregates, but rarely also cubic or octahedral crystals to 1 cm.

Etymology and History

Alabandite was first described in 1784 by Franz-Joseph Müller von Reichenstein
Franz-Joseph Müller von Reichenstein
Franz-Joseph Müller Freiherr von Reichenstein or Franz-Joseph Müller von Reichenstein was an Austrian mineralogist and mining engineer. Müller held several positions in the Austria-Hungarian administration of mines and coinage in the Banat, Transylvania, and Tyrol...

. The mineral name is derived from its supposed discovery locality at Alabanda
Alabanda
Alabanda – also hê Alabanda, ta Alabanda, Alabandeus, Alabandensis, Alabandenus, and for a time, Antiochia of the Chrysaorians – was an ancient city of Caria, Anatolia, the site of which is now located near Doğanyurt , Aydin Province, in the Asian part of Turkey.The city is located in...

 (Aïdin) in Turkey.

Occurrence

Alabandite forms in epithermal polymetallic sulfide vein
Vein (geology)
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...

s and low-temperature manganese deposits. It occurs with acanthite
Acanthite
Acanthite, Ag2S, crystallizes in the monoclinic system and is the stable form of silver sulfide below 173 °C. Argentite is the stable form above that temperature. As argentite cools below that temperature its cubic form is distorted to the monoclinic form of acanthite. Below 173 °C...

, calcite
Calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470°C, and vaterite is even less stable.-Properties:...

, chalcopyrite
Chalcopyrite
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical composition 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.On exposure to air, chalcopyrite...

, galena
Galena
Galena is the natural mineral form of lead sulfide. It is the most important lead ore mineral.Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms...

, pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...

, quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...

, rhodochrosite
Rhodochrosite
Rhodochrosite is a manganese carbonate mineral with chemical composition MnCO3. In its pure form, it is typically a rose-red color, but impure specimens can be shades of pink to pale brown. The streak is white. Its Mohs hardness varies between 3.5 and 4. Its specific gravity is 3.5 to 3.7. It...

, rhodonite
Rhodonite
Rhodonite is a manganese inosilicate, SiO3 and member of the pyroxenoid group of minerals, crystallizing in the triclinic system...

, sphalerite
Sphalerite
Sphalerite is a mineral that is the chief ore of zinc. It consists largely of zinc sulfide in crystalline form but almost always contains variable iron. When iron content is high it is an opaque black variety, marmatite. It is usually found in association with galena, pyrite, and other sulfides...

 and native tellurium. Sometimes it was found in meteorite
Meteorite
A meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...

s.

Localities are several areas in Antarctica, Argentina, Armenia, Australia, Bolivia, Brazil, Bulgaria, Canada, China, Czech Republic, Finland, France, Germany, Ghana, Greece, Greenland, India, Italy, Japan, Kyrgyzstan, Mexico, New Zealand, Norway, Peru, Poland, Romania, Russia, Slovakia, South Africa, South Korea, Sweden, Switzerland, Taiwan, Tanzania, the United Kingdom, the USA, Uzbekistan and Yemen. Altogether at present time approximately 220 discovery sites are registered.

Crystal structure

Alabandite crystallizes in the cubic crystal system in the space group
Space group
In mathematics and geometry, a space group is a symmetry group, usually for three dimensions, that divides space into discrete repeatable domains.In three dimensions, there are 219 unique types, or counted as 230 if chiral copies are considered distinct...

 Fm3m with the lattice parameter
Lattice constant
The lattice constant [or lattice parameter] refers to the constant distance between unit cells in a crystal lattice. Lattices in three dimensions generally have three lattice constants, referred to as a, b, and c. However, in the special case of cubic crystal structures, all of the constants are...

 a = 5.22 Å
Ångström
The angstrom or ångström, is a unit of length equal to 1/10,000,000,000 of a meter . Its symbol is the Swedish letter Å....

 and four formula unit
Formula unit
A formula unit in chemistry is the empirical formula of an ionic or covalent network solid compound used as an independent entity for stoichiometric calculations. It is the lowest whole number ratio of ions represented in an ionic compound...

s per unit cell.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK