Franckeite, chemical formula Pb
5Sn
3Sb
2S
14, belongs to a family of complex
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 ...
s. Franckeite is a
sulfosalt
Sulfosalt minerals are sulfide minerals with the general formula , where
*A represents a metal such as copper, lead, silver, iron, and rarely mercury, zinc, vanadium
*B usually represents semi-metal such as arsenic, antimony, bismuth, and rarely ...
. It is closely related to
cylindrite.
It was first described in 1893 for an occurrence in Chocaya,
Potosí Department
Potosí (; Aymara: ''Putusi''; qu, P'utuqsi) is a department in southwestern Bolivia. It comprises 118,218 km2 with 823,517 inhabitants (2012 census). The capital is the city of Potosí.
It is mostly a barren, mountainous region with on ...
,
Bolivia
, image_flag = Bandera de Bolivia (Estado).svg
, flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center
, flag_alt2 = 7 × 7 square p ...
. It is named after the mining engineers, Carl and Ernest Francke.
[ It can be found in Bolivia at Poopó in Oruro and at Las Aminas, southeast of Chocaya, in Potosi. Franckeite has an average density of 5.7 and can be both grayish black, blackish gray in color.
It occurs in ]hydrothermal
Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek ὕδωρ, ''water'',Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with th ...
silver-tin deposits in Bolivia and in contact metamorphosed limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms w ...
deposit in the Kalkar quarry in California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
. It occurs with cylindrite, teallite, plagionite, zinkenite, cassiterite
Cassiterite is a tin oxide mineral, SnO2. It is generally opaque, but it is translucent in thin crystals. Its luster and multiple crystal faces produce a desirable gem. Cassiterite was the chief tin ore throughout ancient history and remains ...
, wurtzite, pyrrhotite
Pyrrhotite is an iron sulfide mineral with the formula Fe(1-x)S (x = 0 to 0.2). It is a nonstoichiometric variant of FeS, the mineral known as troilite.
Pyrrhotite is also called magnetic pyrite, because the color is similar to pyrite and it i ...
,
marcasite, arsenopyrite
Arsenopyrite ( IMA symbol: Apy) is an iron arsenic sulfide (FeAsS). It is a hard ( Mohs 5.5-6) metallic, opaque, steel grey to silver white mineral with a relatively high specific gravity of 6.1. When dissolved in nitric acid, it releases elem ...
, galena
Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver.
Galena is one of the most abundant and widely distributed sulfide minerals. It cr ...
, pyrite
The mineral pyrite (), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Iron, FeSulfur, S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral.
Pyrite's metallic Luster (mineralogy), lust ...
, sphalerite
Sphalerite (sometimes spelled sphaelerite) is a sulfide mineral with the chemical formula . It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative, Mississippi-V ...
, siderite
Siderite is a mineral composed of iron(II) carbonate (FeCO3). It takes its name from the Greek word σίδηρος ''sideros,'' "iron". It is a valuable iron mineral, since it is 48% iron and contains no sulfur or phosphorus. Zinc, magnesium and ...
and stannite.[
]
See also
*List of minerals
This is a list of minerals for which there are articles on Wikipedia.
Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various ''species''. Within a m ...
*List of minerals named after people
This is a list of minerals named after people. The chemical composition follows name.
A
* Abelsonite: C31H32N4Ni – American physicist Philip Hauge Abelson (1913–2004)alfred
*Abswurmbachite: Cu2+Mn3+6O8SiO4 – German mineralogist I ...
References
Lead minerals
Tin minerals
Antimony minerals
Sulfosalt minerals
Triclinic minerals
Minerals in space group 2
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