Decomposed rock, usually reddish or ferruginous (owing to oxidized pyrites), forming the upper part of a metallic vein. Called also iron hat.
A rusty iron oxide deposit found in the upper parts of veins or forming a cap overlying sulphide mineralization.
The rust-colored capping or staining of a mineral deposit, generally formed by the oxidation or alteration of iron sulphides.
An iron-rich, rusty-coloured, weathering product formed over rocks commonly containing sulphide minerals, in particular iron sulphides.
A rusty, surficial weathering zone which is caused by the weathering of pyrite to produce secondary iron oxide minerals. Since pyrite is often associated with ore deposits, gossans can be a guide to ore.
A ferruginous deposit remaining after the oxidation of the original sulphide minerals in a vein or ore zone.
The rust-coloured oxidized capping or staining of a mineral deposit, generally formed by the oxidation or alteration of iron sulphide.
an exposed, oxidized part of a mineral vein, especially a reddish-colored outcrop of iron ore consisting largely of limonite.
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein. In the classic gossan or iron cap all that remains is iron oxides and quartz often in the form of boxworks, quartz lined cavities retaining the shape of the dissolved ore minerals. In other cases quartz and iron oxides, limonite, goethite, and jarosite, exist as pseudomorphs replacing the pyrite and primary ore minerals.