mineral

Pyrite-bearing sulfide ore (likely pyrite with iron oxides)

Pyrite, FeS₂, possibly mixed with limonite/goethite and other sulfides

AI-generated identification · may be incorrect

Brassy yellow metallic luster, irregular granular/massive texture, and apparent conchoidal-to-uneven fracture; pyrite has Mohs hardness 6–6.5, cubic crystal structure, and specific gravity about 5.0. The gray matrix and dull yellow-brown weathering suggest oxidation or associated host rock.

Identified August 16, 2026More mineral →

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Physical properties

Formation & geological history

Pyrite forms in hydrothermal veins, sedimentary rocks, and metamorphic environments when sulfur-rich fluids react with iron; associated iron oxides develop through weathering. Its age cannot be determined from the photograph and depends on the host deposit.

Uses & applications

Used historically as a sulfur and iron source, though now mainly collected as a mineral specimen; attractive crystals may be used decoratively. It is generally not a gemstone because it tarnishes and can oxidize.

Geological facts

Often called “fool’s gold,” pyrite is denser and harder than gold and commonly leaves a dark greenish-black streak rather than a yellow one. It may produce a sulfurous odor or sparks when struck, but testing can damage the specimen.

Field identification & locations

Likely pyrite if the yellow areas are metallic and heavy; a streak test, hardness test, and inspection for cubic crystals would help confirm it. Common worldwide in Peru, Spain, Italy, the United States, and China.