Argyrodite is an uncommon
silver
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, whi ...
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 s ...
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, the ...
with formula Ag
8GeS
6. 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 ...
,
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 betwe ...
.
[
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 ...
under the name "Plusinglanz", and Bolivian crystals were incorrectly described in 1849 as crystallized brongniardite.
Isomorphous with argyrodite is the corresponding tin
Tin is a chemical element with the symbol Sn (from la, stannum) and atomic number 50. Tin is a silvery-coloured metal.
Tin is soft enough to be cut with little force and a bar of tin can be bent by hand with little effort. When bent, t ...
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, macrosc ...
, 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 (Cu4.7Ag3.3)GeS6.
Argyrodite gets its name from the Greek words that loosely translate into "rich in silver
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, whi ...
".[
]
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 solid el ...
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