Mineral Species: Siderite

Chemical Formula: FeCO3

Chemical Name: Iron Carbonate

Mineral Class: Carbonate

Mineral Notes: Siderite has the same crystal structure as Calcite, except that Fe 2+ ions replace Ca 2+ in the metal positions. It is found in bedded sedimentary iron ores and as a vein deposit with other metal ores. It is a major iron ore mineral and is often mined for its metal content. It is also significanlty easier to smelt than other iron ores.

Description: A superb specimen of Siderite. The mineral shows a very unusual botryoidal form on matrix. The clusters are extremely-well formed and have a strong luster. Where one is part formed, a layered structure is easily seen. A must-have display specimen.

Location: Treamble Mine, Perran Iron Lode, Perranporth, Cornwall, England.