Fe2+ CO3

Sideritec 2001-2005 Mineral Data Publishing, version 1

Crystal Data: Hexagonal. Point Group: 3 2/m. Commonly crystallized, typicallyrhombohedral {1011} to steep scalenohedral {2131}, prismatic {1010}, {0001}, with additional
minor forms, to 25 cm; fibrous, stalactitic, spherulitic, cleavable, fine-grained massive.
Twinning: Uncommon on {0112}, lamellar; rare on {0001}.
Physical Properties:
Cleavage: Perfect on {1011}. Fracture: Uneven to conchoidal.
Tenacity: Brittle. Hardness = 3.75–4.25 D(meas.) = 3.96(1) D(calc.) = 3.932
Optical Properties: Translucent. Color: Yellowish brown, brown; white, ash-gray,yellowish gray, pale green; colorless, yellow, yellow-brown in transmitted light. Streak: White.
Luster: Vitreous, may be pearly or silky.
Optical Class: Uniaxial (–). Dispersion: Strong. ω = 1.875  = 1.633
Cell Data:

Space Group: R3c. a = 4.6916–4.6935

c = 15.3796–15.3860

Z=6

X-ray Powder Pattern: Ivigtut, Greenland.
2.795 (100), 1.7315 (35), 1.7382 (30), 3.593 (25), 2.346 (20), 2.134 (20), 1.9650 (20)
Chemistry:CO2FeO
MnO
MgO
CaO
Total
(1) Camborne, England. (2) FeCO3 .
Polymorphism & Series:
smithsonite.
Mineral Group:

(1)
38.19
61.08
1.12
0.13
0.10

(2)
37.99
62.01

100.62100.00Forms three series, with magnesite, with rhodochrosite, and withCalcite group.

Occurrence: A common component of bedded sedimentary iron ores and metamorphic ironformations; in hydrothermal metallic veins; rarely in granite and nepheline syenite pegmatites; incarbonatites; authigenic, and in concretions.
Association:

Quartz, barite, fluorite, pyrite.

Distribution: Many noted localities worldwide, including: in Germany, from Freiberg andNeudorf, Harz Mountains, and in the Siegerland district, Westphalia. In Austria, on the Erzberg,
near Eisenerz, Styria, and Hüttenberg-Lölling, Carinthia. From Allevard, Isère, France. InEngland, from many mines in Cornwall, as at the Great Onslow Consols mine, St. Breward,Wheal Maudlin, Lanlivrey, Dolcoath mine, Camborne; from the Virtuous Lady mine, Tavistock,Devon. At Panasqueira, Portugal. From Ivigtut, Greenland. Very large crystals at MontSaint-Hilaire, Quebec, Canada. In the USA, from Bisbee, Cochise Co., and in the Antler mine,
Mohave Co., Arizona; at Leadville, Lake Co., Colorado. From Mosojllacta, Colavi, Bolivia, large
crystals. In Brazil, in the Morro Velho gold mine, Nova Lima, Minas Gerais, and at Pedreira
Ataleia, Governador Valadares.
Name:

From the Greek sideros, for iron in the composition.

References: (1) Palache, C., H. Berman, and C. Frondel (1951) Dana’s system of mineralogy,(7th edition), v. II, 167–171. (2) Deer, W.A., R.A. Howie, and J. Zussman (1962) Rock-forming
minerals, v. 5, non-silicates, 272–277; Chang, L.L.Y., R.A. Howie, and J. Zussman (1996)
Rock-forming minerals, (2nd edition), v. 5B, non-silicates, 163–177. (3) Effenberger, H., K.
Mereiter, and J. Zemann (1981) Crystal structure refinements of magnesite, rhodochrosite,siderite, smithsonite, and dolomite, with discussion of some aspects of the stereochemistry ofcalcite type carbonates. Zeits. Krist., 156, 233–243. (4) (1978) NBS Mono. 25, 15.
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