Rock Identifier
Sulfur-bearing iron ore, likely pyrite-rich gossan (Pyrite (FeS₂) with iron oxides/hydroxides and dark host rock) — mineral
mineral

Sulfur-bearing iron ore, likely pyrite-rich gossan

Pyrite (FeS₂) with iron oxides/hydroxides and dark host rock

AI-generated identification · may be incorrect

Hardness about 6–6.5 for pyrite; typically brassy yellow metallic, while this specimen is dominated by black, brown, and rusty red iron oxides. The irregular massive texture and metallic glints suggest disseminated or massive sulfides rather than distinct crystals;…

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Physical properties

Hardness about 6–6.5 for pyrite; typically brassy yellow metallic, while this specimen is dominated by black, brown, and rusty red iron oxides. The irregular massive texture and metallic glints suggest disseminated or massive sulfides rather than distinct crystals; streak and specific gravity would be needed for confirmation.

Formation & geological history

Likely formed by hydrothermal mineralization, with later weathering producing reddish limonite/goethite gossan around sulfides. Its exact geological age and host formation cannot be determined from the photograph.

Uses & applications

Potentially an ore specimen and educational/collector material; pyrite has historically supplied sulfur and, locally, gold. It is generally unsuitable for jewelry unless well crystallized and stable.

Geological facts

Rusty gossans commonly mark oxidized sulfide deposits beneath the surface. Pyrite can tarnish or deteriorate in humid storage as oxidation generates acidic products.

Field identification & locations

Look for brassy metallic pyrite, a dark greenish-black to brown streak, high density, and occasional cubic crystals; magnetism would suggest associated magnetite rather than pyrite. Common in hydrothermal veins, sedimentary sulfide beds, and metamorphosed ore deposits worldwide.