Stephanite
Encyclopedia
Stephanite is a silver
antimony
sulfosalt mineral with formula: Ag
5Sb
S
4 It is composed of 68.8% silver
, and sometimes is of importance as an ore of this metal.
Schwarzgultigerz), brittle silver-ore (Sprödglanzerz), etc. The name stephanite was proposed by W Haidinger
in 1845 in honour of the Archduke of Austria Stephan Franz Victor
of Habsburg-Lorena (1817-1867). French authors use F. S. Beudant
's name psaturose (from the Greek
ψαθυρός, fragile).
s or flat tables terminated by large basal planes and often modified at the edges by numerous pyramid-planes. Twinning
on the prism-planes is of frequent occurrence, giving rise to pseudo-hexagonal groups like those of aragonite
. The colour is iron-black, and the lustre metallic and brilliant; on exposure to light, however, the crystals soon become dull.
. Associated minerals include proustite
, acanthite
, native silver, tetrahedrite
, galena
, sphalerite
and pyrite
. Localities which have yielded good crystallized specimens are Freiberg and Gersdorf near Rosswein in Saxony
, Chañarcillo
in Chile
, and exceptionally Cornwall
. In the Comstock lode in Nevada
massive stephanite and argentite
are important ores of silver.
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
antimony
Antimony
Antimony is a toxic chemical element with the symbol Sb and an atomic number of 51. A lustrous grey metalloid, it is found in nature mainly as the sulfide mineral stibnite...
sulfosalt mineral with formula: Ag
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
5Sb
Antimony
Antimony is a toxic chemical element with the symbol Sb and an atomic number of 51. A lustrous grey metalloid, it is found in nature mainly as the sulfide mineral stibnite...
S
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
4 It is composed of 68.8% silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
, and sometimes is of importance as an ore of this metal.
History
Under the name Schwarzerz it was mentioned by Georgius Agricola in 1546, and it has been variously known as "black silver ore" (GermanGerman language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....
Schwarzgultigerz), brittle silver-ore (Sprödglanzerz), etc. The name stephanite was proposed by W Haidinger
Wilhelm Karl Ritter von Haidinger
Wilhelm Karl Ritter von Haidinger was an Austrian mineralogist, geologist and physicist....
in 1845 in honour of the Archduke of Austria Stephan Franz Victor
Archduke Stephen, Palatine of Hungary
Palatine Stephen of Hungary or Archduke Stephen Francis Victor of Austria was a member of the House of Habsburg-Lorraine.-Biography:...
of Habsburg-Lorena (1817-1867). French authors use F. S. Beudant
François Sulpice Beudant
François Sulpice Beudant , French mineralogist and geologist, was born in Paris.He was educated at the Ecole Polytechnique and Ecole Normale, and in 1811 was appointed professor of mathematics at the lycée of Avignon. Thence he was called, in 1813, to the lycée of Marseilles to fill the post of...
's name psaturose (from the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
ψαθυρός, fragile).
Properties
It frequently occurs as well-formed crystals, which are orthorhombic and occasionally show indications of hemimorphism: they have the form of six-sided prismPrism (geometry)
In geometry, a prism is a polyhedron with an n-sided polygonal base, a translated copy , and n other faces joining corresponding sides of the two bases. All cross-sections parallel to the base faces are the same. Prisms are named for their base, so a prism with a pentagonal base is called a...
s or flat tables terminated by large basal planes and often modified at the edges by numerous pyramid-planes. Twinning
Crystal twinning
Crystal twinning occurs when two separate crystals share some of the same crystal lattice points in a symmetrical manner. The result is an intergrowth of two separate crystals in a variety of specific configurations. A twin boundary or composition surface separates the two crystals....
on the prism-planes is of frequent occurrence, giving rise to pseudo-hexagonal groups like those of aragonite
Aragonite
Aragonite is a carbonate mineral, one of the two common, naturally occurring, crystal forms of calcium carbonate, CaCO3...
. The colour is iron-black, and the lustre metallic and brilliant; on exposure to light, however, the crystals soon become dull.
Occurrence
Stephanite occurs as a late-stage mineral with other ores of silver in hydrothermal veinsVein (geology)
In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Veins form when mineral constituents carried by an aqueous solution within the rock mass are deposited through precipitation...
. Associated minerals include proustite
Proustite
Proustite is a sulfosalt mineral consisting of silver sulfarsenide, Ag3AsS3, known also as light red silver or ruby silver ore, and an important source of the metal. It is closely allied to the corresponding sulfantimonide, pyrargyrite, from which it was distinguished by the chemical analyses of...
, acanthite
Acanthite
Acanthite, Ag2S, crystallizes in the monoclinic system and is the stable form of silver sulfide below 173 °C. Argentite is the stable form above that temperature. As argentite cools below that temperature its cubic form is distorted to the monoclinic form of acanthite. Below 173 °C...
, native silver, tetrahedrite
Tetrahedrite
Tetrahedrite is a copper antimony sulfosalt mineral with formula: 12Sb4S13. It is the antimony endmember of the continuous solid solution series with arsenic bearing tennantite. Pure endmembers of the series are seldom if ever seen in nature. Of the two, the antimony rich phase is more common...
, galena
Galena
Galena is the natural mineral form of lead sulfide. It is the most important lead ore mineral.Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms...
, sphalerite
Sphalerite
Sphalerite is a mineral that is the chief ore of zinc. It consists largely of zinc sulfide in crystalline form but almost always contains variable iron. When iron content is high it is an opaque black variety, marmatite. It is usually found in association with galena, pyrite, and other sulfides...
and pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...
. Localities which have yielded good crystallized specimens are Freiberg and Gersdorf near Rosswein in Saxony
Saxony
The Free State of Saxony is a landlocked state of Germany, contingent with Brandenburg, Saxony Anhalt, Thuringia, Bavaria, the Czech Republic and Poland. It is the tenth-largest German state in area, with of Germany's sixteen states....
, Chañarcillo
Chañarcillo
Chañarcillo is a town and mine in the Atacama Desert of Copiapó Province, Atacama Region, Chile, located near Vallenar and 75 kilometres from Copiapó. It is noted for its silver mining. The town grew up after the Chañarcillo silver mine was discovered on May 16 1832 by Juan Godoy...
in Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
, and exceptionally Cornwall
Cornwall
Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...
. In the Comstock lode in Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
massive stephanite and argentite
Argentite
Argentite was primarily treated as a mineral belonging to the galena group, cubic silver sulfide , occasionally found as uneven cubes and octahedra, but more often as dendritic or earthy masses, with a blackish lead-grey color and metallic lustre. All these forms are structurally not argentite, but...
are important ores of silver.