Thiospinel group
Encyclopedia
The thiospinel group is a group of sulfide minerals with a general formula AB2X4 where A is nominally a +2 metal, B is a +3 metal and X is -2 sulfide or similar anion (selenide or telluride). Thio refers to sulfur and spinel indicates their isometric
spinel
like structure.
As the chalcogen
s S, Se and Te are less electronegative
than oxygen, the bonding in these materials is generally more covalent
than in the oxospinels. Some are (magnetic
) semiconductor
s but others display, at times complicated, metallic
behavior, often coupled with equally complicated magnetic properties. The assignment of oxidation state
s is also not always as straightforward as in the more ionic
oxocompounds, as is shown in the case of carrollite
.
Group members include:
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....
spinel
Spinel
Spinel is the magnesium aluminium member of the larger spinel group of minerals. It has the formula MgAl2O4. Balas ruby is an old name for a rose-tinted variety.-Spinel group:...
like structure.
As the chalcogen
Chalcogen
The chalcogens are the chemical elements in group 16 of the periodic table. This group is also known as the oxygen family...
s S, Se and Te are less electronegative
Electronegativity
Electronegativity, symbol χ , is a chemical property that describes the tendency of an atom or a functional group to attract electrons towards itself. An atom's electronegativity is affected by both its atomic number and the distance that its valence electrons reside from the charged nucleus...
than oxygen, the bonding in these materials is generally more covalent
Covalent bond
A covalent bond is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms. The stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding....
than in the oxospinels. Some are (magnetic
Magnetism
Magnetism is a property of materials that respond at an atomic or subatomic level to an applied magnetic field. Ferromagnetism is the strongest and most familiar type of magnetism. It is responsible for the behavior of permanent magnets, which produce their own persistent magnetic fields, as well...
) semiconductor
Semiconductor
A semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...
s but others display, at times complicated, metallic
Metallic bond
Metallic bonding is the electrostatic attractive forces between the delocalized electrons, called conduction electrons, gathered in an "electron sea", and the positively charged metal ions...
behavior, often coupled with equally complicated magnetic properties. The assignment of oxidation state
Oxidation state
In chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. The formal oxidation state is the hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic. Oxidation states are typically represented by...
s is also not always as straightforward as in the more ionic
Ionic bond
An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. Ionic bonds are formed between a cation, which is usually a metal, and an anion, which is usually a nonmetal. Pure ionic bonding cannot exist: all ionic compounds have some...
oxocompounds, as is shown in the case of carrollite
Carrollite
Carrollite, CuCo2S4, is a sulfide of copper and cobalt, often with substantial substitution of nickel for the metal ions, and a member of the linnaeite group. It is named after the type locality in Carroll County, Maryland, USA, at the Patapsco mine, Finksburg, Sykesville.- Unit cell :Space group:...
.
Group members include:
- CadmoinditeCadmoinditeCadmoindite is a rare cadmium indium sulfide mineral discovered in Siberia around the vent of a high-temperature fumarole at the Kudriavy volcano, Iturup Island in the Kuril Islands. It has also been reported from the Kateřina Coal Mine in Bohemia, Czech Republic....
- CdIn2S4 - CarrolliteCarrolliteCarrollite, CuCo2S4, is a sulfide of copper and cobalt, often with substantial substitution of nickel for the metal ions, and a member of the linnaeite group. It is named after the type locality in Carroll County, Maryland, USA, at the Patapsco mine, Finksburg, Sykesville.- Unit cell :Space group:...
- CuCo2S4 - FletcheriteFletcheriteFletcherite is a rare thiospinel sulfide mineral with formula Cu2S4. It is an opaque metallic steel gray mineral which crystallizes in the Cubic crystal system...
- Cu(Ni,Co)2S4 - GreigiteGreigiteGreigite is an iron sulfide mineral with formula Fe3S4. It is the sulfur equivalent of the iron oxide magnetite . It was first described in 1964 for an occurrence in San Bernardino County, California, and named after the mineralogist and physical chemist Joseph W...
- Fe2+Fe3+2S4 - InditeInditeIndite is an extremely rare indium-iron sulfide mineral, found in Siberia. Its chemical formula is FeIn2S4.It occurs as replacement of cassiterite in hydrothermal deposits. It is associated with dzhalindite, cassiterite and quartz...
- FeIn2S4 - KalininiteKalininiteKalininite is a thiospinel mineral found in Russia.- References :**...
- ZnCr2S4 - LinnaeiteLinnaeiteLinnaeite is a cobalt sulfide mineral with the composition Co+2Co+32S4 . It was discovered in 1845 in Västmanland, Sweden, and was named to honor Carl Linnaeus ....
- Co2+Co23+S4 - PolydymitePolydymitePolydymite, Ni2+Ni23+S4, is a supergene thiospinel sulfide mineral associated with the weathering of primary pentlandite nickel sulfide.Polydymite crystallises in the isometric system, with a hardness of 4.5 to 5.5 and a specific gravity of about 4, is dark violet gray to copper-red, often with...
- Ni2+Ni23+S4 - SiegeniteSiegeniteSiegenite is a cobalt nickel sulfide mineral with formula: 3S4 . It was found at the Browns deposit, Batchelor, Northern Territory, Australia....
- (Ni,Co)3S4 - TyrrelliteTyrrelliteTyrrellite is a selenide mineral that has a formula of Cu2Se4. It has been found in the Goldfields District in northern Saskatchewan, as well as in the Petrovice deposit, Czech Republic. It is named after the Canadian geologist Joseph Burr Tyrrell...
- Cu(Co,Ni)2Se4 - ViolariteViolariteViolarite is a supergene sulfide mineral associated with the weathering and oxidation of primary pentlandite nickel sulfide ore minerals....
- Fe2+Ni23+S4