siderite

siderite

[sid-uh-rahyt]
siderite or chalybite, a mineral, varying in color from brown, green, or gray to black and occurring in nature in massive and crystalline form. A carbonate of iron, FeCO3, it serves as an iron ore, especially in the British Isles. It is widely distributed, being found also in the United States, Europe, South America, and Australia.
or chalybite

Iron carbonate (FeCO3), a widespread carbonate mineral that can be an ore of iron. The mineral commonly occurs in thin beds with shales, clay, or coal seams (as sedimentary deposits) and in hydrothermal metallic veins (as gangue, or waste rock).

Learn more about siderite with a free trial on Britannica.com.

Siderite is also the name of a type of iron meteorite.

Siderite is a mineral composed of iron carbonate FeCO3. It takes its name from the Greek word sideros, “iron”. It is a valuable iron mineral, since it is 48% iron and contains no sulfur or phosphorus. Both magnesium and manganese commonly substitute for the iron.

Siderite has Mohs hardness of 3.5-4, a specific gravity of 3.8, a white streak and a vitreous or pearly luster.

Its crystals belong to the hexagonal system, and are rhombohedral in shape, typically with curved and striated faces. It also occurs in masses. Color ranges from yellow to dark brown or black, the latter being due to the presence of manganese (sometimes called manganosiderite).

Siderite is commonly found in hydrothermal veins, and is associated with barite, fluorite, galena, and others. It is also a common diagenetic mineral in shales and sandstones, where it sometimes forms concretions. In sedimentary rocks, siderite commonly forms at shallow burial depths and its elemental composition is often related to the depositional environment of the enclosing sediments (Mozley, 1989). In addition, a number of recent studies have used the oxygen isotopic composition of sphaerosiderite (a type associated with soils) as a proxy for the isotopic composition of meteoric water shortly after deposition (e.g., Ludvigson et al., 1998).

References

  • Ludvigson, G.A., Gonzalez, L.A. Metzger, R.A., Witzke, B.J., Brenner, R.L., Murillo, A.P.and White, T.S., 1998, Meteoric sphaerosiderite lines and their use for paleohydrology and paleoclimatology: Geology, v. 26, p. 1039-1042.
  • Mozley, P.S., 1989, Relation between depositional environment and the elemental composition of early diagenetic siderite: Geology, v. 17, p. 704- 706.
  • The Complete Book of Science, American Education Publishing, Columbus, Ohio 2005

External links

Search another word or see Sideriteon Dictionary | Thesaurus |Spanish
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature