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Gossan identification and geology

An intensely oxidized, weathered cap of rock overlying a sulfide ore deposit, typically characterized by a porous, cellular texture and vivid red, yellow, and brown colors from iron oxide minerals goethite, limonite, hematite, jarosite . Gossans form when sulfide minerals at the surface are destroyed by oxidation and the iron released is precipitated as insoluble oxides, while other metals may be leached downward to form supergene enrichment zones. Field: economic geology. Example: The gossan at the Rio Tinto mine in Spain was the first indicator of the massive sulfide deposit beneath, and its characteristic red color gave the river and the mine its name—'Red River.'. Related terms: Supergene enrichment, Oxidation zone, Limonite, Sulfide.

Sources, scope & corrections

These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.

Editorial owner
GeoMiner
Last updated
2026-03-30T15:19:41.999576+00:00
Review status
Published; not independently peer-reviewed
  • USGS Thesaurus — U.S. Geological Survey. Controlled earth-science terminology used to describe USGS information resources.
  • Glossary of Geologic Terms — U.S. National Park Service. Geologic definitions prepared by the NPS Geologic Resources Inventory.

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Common questions

What does Gossan mean in geology?
An intensely oxidized, weathered cap of rock overlying a sulfide ore deposit, typically characterized by a porous, cellular texture and vivid red, yellow, and brown colors from iron oxide minerals goethite, limonite, hematite, jarosite . Gossans form when sulfide minerals at the surface are destroyed by oxidation and the iron released is precipitated as insoluble oxides, while other metals may be leached downward to form supergene enrichment zones.
What is an example of Gossan?
The gossan at the Rio Tinto mine in Spain was the first indicator of the massive sulfide deposit beneath, and its characteristic red color gave the river and the mine its name—'Red River.'
Which earth-science field uses the term Gossan?
Gossan is used in economic geology.
Which terms are related to Gossan?
Related terms in this reference are Supergene enrichment, Oxidation zone, Limonite, Sulfide.

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