Argyrodite is an uncommon

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 ...

germanium Germanium is a chemical element with the symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid in the carbon group that is chemically similar to its group neighbors ...

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 ...

with formula Ag₈GeS₆. The color is iron-black with a purplish tinge, and the luster metallic. Discovered by

Clemens Winkler Clemens Alexander Winkler (December 26, 1838 – October 8, 1904) was a German chemist who discovered the element germanium in 1886, solidifying Dmitri Mendeleev's theory of periodicity. Life Winkler was born in 1838 in Freiberg, Kingdom ...

in 1886, it is of interest as it was described shortly after the element germanium was isolated, 15 years after it had been postulated by

Mendeleev Dmitri Ivanovich Mendeleev (sometimes transliterated as Mendeleyev or Mendeleef) ( ; russian: links=no, Дмитрий Иванович Менделеев, tr. , ; 8 February Old_Style_and_New_Style_dates">O.S._27_January.html" ;"title="O ...

. It was first described for an occurrence in the Himmelsfürst Mine, Erzgebirge,

Freiberg, Saxony Freiberg is a university and former mining town in Saxony, Germany. It is a so-called ''Große Kreisstadt'' (large county town) and the administrative centre of Mittelsachsen district. Its historic town centre has been placed under heritage c ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...

. The Freiberg mineral had previously been imperfectly described by

August Breithaupt Johann Friedrich August Breithaupt (May 16, 1791 – September 22, 1873) was a German mineralogist and professor at Freiberg Mining Academy in Freiberg, Saxony. Biography He was born in Probstzella. He received his doctorate at the Universities o ...

under the name "Plusinglanz", and Bolivian crystals were incorrectly described in 1849 as crystallized brongniardite. Isomorphous with argyrodite is the corresponding tin bearing mineral Ag₈SnS₆, also found in Bolivia as pseudocubic

crystals A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...

, and known by the name

canfieldite Canfieldite is a rare silver tin sulfide mineral with formula: Ag8SnS6. The mineral typically contains variable amounts of germanium substitution in the tin site and tellurium in the sulfur site. There is a complete series between canfieldite and ...

. There is also a related mineral, putzite, with composition (Cu_4.7Ag_3.3)GeS₆. Argyrodite gets its name from the Greek words that loosely translate into "rich in

Argyrodite-type material

The term argyrodite is also used for other materials with a similar crystal structure, in particular

lithium Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense soli ...

based argyrodite-type materials, which have received interest from researchers as a potential solid-state electrolyte for

lithium-ion batteries A lithium-ion or Li-ion battery is a type of rechargeable battery which uses the reversible reduction of lithium ions to store energy. It is the predominant battery type used in portable consumer electronics and electric vehicles. It also se ...

. They are considered to be of the form: With x between 0 and 1, B denoting either phosphor or arsenic, Ch for sulfur or selenium and X for chlorine, bromine or iodine.

References

Attribution: *{{EB1911, first=Leonard James , last=Spencer , authorlink=Leonard James Spencer , wstitle=Argyrodite , volume=2 , page=488 Silver minerals Sulfide minerals Germanium minerals Orthorhombic minerals Minerals in space group 33