Chemical elements
    History of Iron
      Native Iron
      Iron Minerals
      Sources of Iron
    Physical Properties
    Chemical Properties
    Iron Salts
    PDB 101m-1aeb
    PDB 1aed-1awd
    PDB 1awp-1beq
    PDB 1bes-1c53
    PDB 1c6o-1ci6
    PDB 1cie-1cry
    PDB 1csu-1dfx
    PDB 1dgb-1dry
    PDB 1ds1-1e08
    PDB 1e0z-1ehj
    PDB 1ehk-1f5o
    PDB 1f5p-1fnp
    PDB 1fnq-1fzi
    PDB 1g08-1gnl
    PDB 1gnt-1h43
    PDB 1h44-1hdb
    PDB 1hds-1i5u
    PDB 1i6d-1iwh
    PDB 1iwi-1jgx
    PDB 1jgy-1k2o
    PDB 1k2r-1kw6
    PDB 1kw8-1lj0
    PDB 1lj1-1m2m
    PDB 1m34-1mko
    PDB 1mkq-1mun
    PDB 1muy-1n9x
    PDB 1naz-1nx4
    PDB 1nx7-1ofe
    PDB 1off-1p3t
    PDB 1p3u-1pmb
    PDB 1po3-1qmq
    PDB 1qn0-1ra0
    PDB 1ra5-1rxg
    PDB 1ry5-1smi
    PDB 1smj-1t71
    PDB 1t85-1u8v
    PDB 1u9m-1uyu
    PDB 1uzr-1vxf
    PDB 1vxg-1wri
    PDB 1wtf-1xlq
    PDB 1xm8-1y4r
    PDB 1y4t-1ygd
    PDB 1yge-1z01
    PDB 1z02-2a9e
    PDB 2aa1-2azq
    PDB 2b0z-2boz
    PDB 2bpb-2ca3
    PDB 2ca4-2cz7
    PDB 2czs-2dyr
    PDB 2dys-2ewk
    PDB 2ewu-2fwl
    PDB 2fwt-2gl3
    PDB 2gln-2hhb
    PDB 2hhd-2ibn
    PDB 2ibz-2jb8
    PDB 2jbl-2mgh
    PDB 2mgi-2o01
    PDB 2o08-2ozy
    PDB 2p0b-2q0i
    PDB 2q0j-2r1h
    PDB 2r1k-2spm
    PDB 2spn-2vbd
    PDB 2vbp-2vzb
    PDB 2vzm-2wiv
    PDB 2wiy-2xj5
    PDB 2xj6-2ylj
    PDB 2yrs-2zon
    PDB 2zoo-3a17
    PDB 3a18-3aes
    PDB 3aet-3bnd
    PDB 3bne-3cir
    PDB 3ciu-3dax
    PDB 3dbg-3e1p
    PDB 3e1q-3eh4
    PDB 3eh5-3fll
    PDB 3fm1-3gas
    PDB 3gb4-3h57
    PDB 3h58-3hrw
    PDB 3hsn-3ir6
    PDB 3ir7-3k9y
    PDB 3k9z-3l4p
    PDB 3l61-3lxi
    PDB 3lyq-3mm8
    PDB 3mm9-3n62
    PDB 3n63-3nlo
    PDB 3nlp-3o0f
    PDB 3o0r-3p6o
    PDB 3p6p-3prq
    PDB 3prr-3sel
    PDB 3sik-3una
    PDB 3unc-4blc
    PDB 4cat-4erg
    PDB 4erm-4nse
    PDB 4pah-8cat
    PDB 8cpp-9nse


Carbonates consist essentially of ferrous carbonate, FeCO3, the purest form of which is spathic iron ore, which occurs both in the crystalline and the massive form. It is mined in Russia, Poland, the Balkans, Styria (Austria), Westphalia, and other parts of Germany. Its phosphorus content is low, but a considerable quantity of manganese is present. It is usually of a light brown colour and is possessed of a pearly lustre.

Stvrian ore is obtained by quarrying, there being three kinds of veins, each several yards in thickness, the richest of which contains some 45 per cent, of metallic iron. In 1913 the production of ore amounted to 1,950,000 tons. It is estimated that the reserve of rich ore exceeds 200 million tons. It is practically free from sulphur, contains 0.01 per cent, of phosphorus and 2.23 per cent, of manganese.

When crystalline, spathic ore is known as siderite or chalybite. The crystals belong to the hexagonal system

a = 0.81715,

and Cornwall has yielded many fine specimens.

The theoretical percentage of metallic iron is 48.3. Hardness 3.5 to 4.5; density 3.7 to 3.9. It is brown or grey in colour and leaves a white streak. It readily oxidises when wet, being converted into limonite. Siderite from East Pool Mine, Cornwall, has been found containing cobalt, nickel, and even indium and rubidium in small quantity.

The spathic ores of the Brendon Hills, West Somerset, were at one time worked largely for the manufacture of Spiegeleisen, as they contained some 12 per cent, of manganese, probably as carbonate, since ferrous and manganese carbonates are isomorphous. The ore was worked in early times, perhaps by the Romans.

Staffordshire, West Yorkshire, and South Wales, yield an argillaceous iron ore, also known as clay iron stone, which contains some 10 per cent, of clay and from 30 to 40 per cent, of metallic iron. The Staffordshire ore has many local names; when found in concretionary and globular masses it is called sphaero-siderite. It contains about 0.25 per cent, of phosphorus. Cleveland iron stone is one of the lowest grades of ore worked for iron in this country, and contains about 33 per cent, of metallic iron. It occurs in bands in the Middle Lias, the most important band being nearly 20 feet thick. Its phosphorus content is high, averaging 0.75 per cent. The bluish-green colour of the ore is due to ferrous silicate. Traces of zinc, gallium, nickel, and cobalt have been detected in the ore.

Under the microscope the ore has an appearance suggestive of oolitic limestone, from which it has very probably been formed by molecular replacement of the calcium carbonate by ferrous carbonate, through the infiltration of waters containing the latter in solution.

Beneath the brown haematite ores of Northamptonshire, an impure unaltered ferrous carbonate deposit occurs which is bluish or greenish- grey in appearance. The depth at which it lies represents the depth to which weathering or oxidation of the upper layers has occurred.

A clay iron stone containing some 35 per cent, of iron has been worked from Roman times, if not earlier, in the Weald of Sussex and Kent, charcoal being used as the fuel.

In Linlithgow and Lanark a clay iron stone occurs, impregnated with some 15 per cent, of carbonaceous matter. It is also found in North Staffordshire and in South Wales, and is known as blackband iron stone. The carbonaceous material present is often sufficient to allow the ore to be calcined without the further addition of fuel. A product containing 50 to 70 per cent, of iron is yielded.

An ore, containing magnesium carbonate in the proportion represented by the formula 2FeCO3.MgCO3, is known as sidero-plesite, and has been found at Salzburg and in Nova Scotia. Pistomesite, FeCO3.MgCO3, is found at Salzburg and Piedmont; and mesitite, FeCO3.2MgCO3, at Piedmont. Ankerite is 2CaCO3.MgCO3.FeCO3.

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