cobalt
Cobalt is a chemical element with the symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, p ...
sulfide mineral
The sulfide minerals are a class of minerals containing sulfide (S2−) or disulfide (S22−) as the major anion. Some sulfide minerals are economically important as metal ores. The sulfide class also includes the selenides, the tellurides, th ...
found in the
Democratic Republic of Congo
The Democratic Republic of the Congo (french: République démocratique du Congo (RDC), colloquially "La RDC" ), informally Congo-Kinshasa, DR Congo, the DRC, the DROC, or the Congo, and formerly and also colloquially Zaire, is a country in ...
. It was discovered together with the
nickel sulfide
Nickel sulfide is any inorganic compound with the formula NiSx. They range in color from bronze (Ni3S2) to black (NiS2). The nickel sulfide with simplest stoichiometry is NiS, also known as the mineral millerite. From the economic perspective, ...
vaesite
Vaesite ( Ni S2) is a mineral found together with cattierite in the Democratic Republic of Congo. It is named after Johannes F. Vaes, a Belgian mineralologist. It is part of the pyrite group
The pyrite group of minerals is a set of cubic crystal ...
pyrite group
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.
The group is n ...
, in which all minerals share the same building principle. The metal in the oxidation state +2 forms a
sodium chloride
Sodium chloride , commonly known as salt (although sea salt also contains other chemical salts), is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. With molar masses of 22.99 and 35. ...
structure together with the anion S22−. This formalism recognizes that the sulfur atoms in pyrite occur in pairs with clear S-S bonds.
It occurs with
pyrite
The mineral pyrite (), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Iron, FeSulfur, S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral.
Pyrite's metallic Luster (mineralogy), lust ...
,
chalcopyrite
Chalcopyrite ( ) 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 Mo ...
and members of the
linnaeite
Linnaeite is a cobalt
Cobalt is a chemical element with the symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iro ...
–
polydymite
Polydymite, 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 abo ...
group in ore deposits in
carbonate rock
Carbonate rocks are a class of sedimentary rocks composed primarily of carbonate minerals. The two major types are limestone, which is composed of calcite or aragonite (different crystal forms of CaCO3), and dolomite rock (also known as dolosto ...
s. In addition to the type locality in the Katanga district it is reported from Gansberg,
Black Forest
The Black Forest (german: Schwarzwald ) is a large forested mountain range in the state of Baden-Württemberg in southwest Germany, bounded by the Rhine Valley to the west and south and close to the borders with France and Switzerland. It is ...
, Germany; near
Filipstad
Filipstad is a locality and the seat of Filipstad Municipality, Värmland County, Sweden, with 10,644 inhabitants in 2019.
Filipstad was granted city privileges in 1611 by Charles IX of Sweden, who named it after his son Duke Carl Philip (1601&n ...
Sparta
Sparta ( Doric Greek: Σπάρτα, ''Spártā''; Attic Greek: Σπάρτη, ''Spártē'') was a prominent city-state in Laconia, in ancient Greece. In antiquity, the city-state was known as Lacedaemon (, ), while the name Sparta referr ...
Reynolds County, Missouri
Reynolds County is a county located in the Ozark Foothills Region in the Lead Belt of Missouri. As of the 2020 census, the population was 6,096. Its county seat is Centerville. The county was officially organized on February 25, 1845, and was ...