Oxidized zone (gossan)

Ore deposit

Above the water table, rain water oxidises the sulfides of an ore body: a rusty iron cap (gossan) at the top, then a leached zone, an oxidized zone of colourful carbonates, sulfates and oxides, and at the water table a zone enriched in copper sulfides. Prospectors read gossans as signs of the ore below.

Rocks

Limonite, Psilomelane

Minerals

Goethite, Malachite, Azurite, Cuprite, Chalcocite, Covellite, Pyrolusite, Manganite, Chrysocolla, Vanadinite, Wulfenite, Dioptase, Smithsonite, Cerussite, Hemimorphite, Mimetite, Pyromorphite, Crocoite, Chlorargyrite, Anglesite, Erythrite, Heterogenite

Metals

Cobalt, Copper, Iron, Lead, Manganese, Molybdenum, Silver, Vanadium, Zinc

Worked

Before and since the industrial age

Sources

• Gossan. Wikipedia.
• Supergene (geology). Wikipedia.

Browse the Crystal Encyclopedia — MGS Toolbox