Alluaudite is a relatively common

alkaline In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a base (chemistry), basic, ionic compound, ionic salt (chemistry), salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as ...

manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...

phosphate mineral Phosphate minerals contain the tetrahedrally coordinated phosphate (PO43−) anion along sometimes with arsenate (AsO43−) and vanadate (VO43−) substitutions, and chloride (Cl−), fluoride (F−), and hydroxide (OH−) anions that also fit i ...

with the chemical formula . It occurs as

metasomatic Metasomatism (from the Greek μετά ''metá'' "change" and σῶμα ''sôma'' "body") is the chemical alteration of a rock by hydrothermal and other fluids. It is the replacement of one rock by another of different mineralogical and chemical com ...

replacement in granitic

pegmatites A pegmatite is an igneous rock showing a very coarse texture, with large interlocking crystals usually greater in size than and sometimes greater than . Most pegmatites are composed of quartz, feldspar, and mica, having a similar silicic comp ...

and within phosphatic

nodules Nodule may refer to: *Nodule (geology), a small rock or mineral cluster *Manganese nodule, a metallic concretion found on the seafloor *Nodule (medicine), a small aggregation of cells *Root nodule Root nodules are found on the roots of plants, p ...

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...

s. It was first described in 1848 for an occurrence in

Skellefteå Skellefteå (, locally ) is a Cities in Sweden, city in Västerbotten County, Sweden. It is the seat of Skellefteå Municipality, which had 73,246 inhabitants in 2021. The city is historically industrial, with mining being a large part of that i ...

Västerbotten Västerbotten (), known in English as West Bothnia or Westrobothnia, is a province (''landskap'') in the north of Sweden, bordering Ångermanland, Lapland, North Bothnia, and the Gulf of Bothnia. It is known for the cheese named after the provi ...

Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...

. It was named by

Alexis Damour Augustin Alexis Damour (19 July 1808, in Paris – 22 September 1902, in Paris) was a French mineralogist who was also interested in prehistory. Biography In 1827 he studied under Alexandre Brongniart at the Muséum d'Histoire Naturelle in ...

after François Alluaud (II) (1778–1866).Alluaudite on Mindat.org
/ref>Alluaudite in the Handbook of Mineralogy
/ref> The mineral structure was first described in 1955.

References

Phosphate minerals Manganese(II) minerals Iron(II,III) minerals Sodium minerals Monoclinic minerals Minerals in space group 15 Minerals described in 1848 {{phosphate-mineral-stub