Ferrous Carbonate (CAS: 563-71-3)

Ferrous Carbonate is a mineral composed of iron(II) carbonate (FeCO3). It takes

its name from the Greek word σίδηροςsideros, “iron”. It is a valuable iron mineral,

since it is 48% iron and contains no sulfur or phosphorus. Bothmagnesium and 

manganese commonly substitute for the iron.

Siderite has Mohs hardness of 3.75-4.25, a specific gravity of 3.96, a white streak and

a vitreous lustre or pearlyluster.

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 thedepositional environment 

of the enclosing sediments. 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 ofmeteoric water shortly after deposition.