Rosasite is a

carbonate mineral Carbonate minerals are those minerals containing the carbonate ion, . Carbonate divisions Anhydrous carbonates *Calcite group: trigonal **Calcite CaCO3 **Gaspéite (Ni,Mg,Fe2+)CO3 **Magnesite MgCO3 **Otavite CdCO3 **Rhodochrosite MnCO3 **Sider ...

with minor potential for use as a

zinc Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic tabl ...

and

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

ore Ore is natural rock or sediment that contains one or more valuable minerals, typically including metals, concentrated above background levels, and that is economically viable to mine and process. The grade of ore refers to the concentration ...

. Chemically, it is a copper zinc

carbonate A carbonate is a salt of carbonic acid, (), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate group ...

hydroxide Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. It ...

with a copper to zinc ratio of 3:2, occurring in the secondary

oxidation Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is ...

zone of copper-zinc deposits. It was originally discovered in 1908 in the Rosas mine in

Sardinia Sardinia ( ; ; ) is the Mediterranean islands#By area, second-largest island in the Mediterranean Sea, after Sicily, and one of the Regions of Italy, twenty regions of Italy. It is located west of the Italian Peninsula, north of Tunisia an ...

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

, and is named after the location. Fibrous blue-green rosasite crystals are usually found in globular aggregates, often associated with red

limonite Limonite () is an iron ore consisting of a mixture of hydrated iron(III) oxide-hydroxides in varying composition. The generic formula is frequently written as , although this is not entirely accurate as the ratio of oxide to hydroxide can vary qu ...

and other colorful

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Mi ...

s. It is very similar to

aurichalcite Aurichalcite is a carbonate mineral, usually found as a secondary mineral in copper and zinc deposits. Its chemical formula is . The zinc to copper ratio is about 5:4. Copper (Cu2+) gives aurichalcite its green-blue colors. Occurrence Aurichalci ...

, but can be distinguished by its superior hardness.

References

Mineral galleries
Copper(II) minerals Zinc minerals Carbonate minerals Monoclinic minerals Minerals in space group 14 Minerals described in 1908 {{Carbonate-mineral-stub