Auricupride is a natural

alloy An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductilit ...

that combines

copper Copper is a chemical element with the symbol Cu (from la, cuprum) 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 pinkis ...

and

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile me ...

. Its

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbol ...

is Cu₃Au. The alloy crystallizes in the cubic crystal system in the L1₂ structure type and occurs as malleable grains or platey masses. It is an opaque yellow with a reddish tint. It has a hardness of 3.5 and a specific gravity of 11.5.http://www.handbookofmineralogy.org/pdfs/auricupride.pdf Handbook of Mineralogy A variant called ''tetra-auricupride'' (CuAu) exists.

Silver Silver is a chemical element with the symbol Ag (from the Latin ', derived from the Proto-Indo-European ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical ...

may be present resulting in the variety ''argentocuproauride'' (). It was first described in 1950 for an occurrence in the

Ural Mountains The Ural Mountains ( ; rus, Ура́льские го́ры, r=Uralskiye gory, p=ʊˈralʲskʲɪjə ˈɡorɨ; ba, Урал тауҙары) or simply the Urals, are a mountain range that runs approximately from north to south through western ...

Russia. It occurs as low temperature ''unmixing'' product in

serpentinite Serpentinite is a rock composed predominantly of one or more serpentine group minerals, the name originating from the similarity of the texture of the rock to that of the skin of a snake. Serpentinite has been called ''serpentine'' or ''se ...

s and as reduction "halos" in

redbed Red beds (or redbeds) are sedimentary rocks, typically consisting of sandstone, siltstone, and shale, that are predominantly red in color due to the presence of ferric oxides. Frequently, these red-colored sedimentary strata locally contain th ...

deposits. It is most often found in

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...

Cyprus Cyprus ; tr, Kıbrıs (), officially the Republic of Cyprus,, , lit: Republic of Cyprus is an island country located south of the Anatolian Peninsula in the eastern Mediterranean Sea. Its continental position is disputed; while it is ge ...

, Switzerland and

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...

References

External links

National Pollutant Inventory - Copper and compounds fact sheet
Copper alloys Gold minerals Native element minerals Cubic minerals Minerals in space group 221 Minerals described in 1950 {{alloy-stub