Great Oakley. Sussex, Britain

Siderite nodules are common within the Cretaceous Grinstead Clay Formation and were smelted to make iron. This weathered clay ironstone nodule was excavated from an Anglo-Saxon smelting site.

Major Minerals:

Siderite, limonite

Minor Minerals:

Pyrite, marcasite


The concentric banding of the nodule is typical. Carbonates have been replaced by limonite to form an outermost weathering crust. Framboidal pyrite, marcasite and pyrite infilling vugs are widespread but minor in extent.


Tebbutt, 1982