Collection: Siderite

Siderite is an important mineral and iron ore .

🔍 Identification of siderite

• Chemical formula : FeCO₃ (iron carbonate)

• Crystal system : Trigonal

• Color : Yellowish brown to dark brown, sometimes gray or pale green

• Luster : Vitreous to pearly

• Hardness (Mohs scale) : 3.5 to 4.5

• Density : Approx. 3.8 g/cm³

🪨 Formation and deposits

Siderite is formed mainly in:

• low to medium temperature hydrothermal veins ;

• sedimentary environments , particularly in association with other iron minerals (hematite, goethite);

• metamorphic rocks , sometimes altered.

It is often associated with calcite , dolomite , pyrite , and galena .

⚒️ Use

• Iron ore : It contains about 48% iron, making it a source that is exploited in some areas.

• Less used today than hematite or magnetite, because:

  • it requires calcination (heating to remove CO₂) before being used in blast furnaces;

  • its iron content is lower than that of the oxides.

🌍 Main deposits

• Europe: Germany (historically in the Siegerland region), United Kingdom (Cornwall), France (Lorraine)

• United States, Brazil, Russia, China, etc.