mineral

Pyrite-bearing quartz or sulfide-rich rock

Pyrite (FeS₂) in quartz-rich matrix, possibly with chalcopyrite

AI-generated identification · may be incorrect

Granular, metallic gray-gold and silvery surfaces with rusty oxidation; likely hardness 6–6.5 for pyrite and about 7 for quartz, with no obvious cleavage and relatively high specific gravity. The irregular massive texture suggests an ore specimen rather than a single crystal.

Identified September 7, 2026More mineral →

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Physical properties

Formation & geological history

Formed when sulfur-rich hydrothermal fluids deposited iron sulfides in fractures, commonly during hydrothermal vein formation; its exact geological age cannot be determined from the photograph. Oxidation of exposed sulfides produces the brown-yellow weathering visible here.

Uses & applications

Collected as an ore specimen and teaching sample; pyrite is used mainly as a sulfur source and historically for sulfuric-acid production, while quartz is used in glass, ceramics, and electronics.

Geological facts

Pyrite is commonly called “fool’s gold,” but its brassy color and metallic luster distinguish it from gold. The specimen may also contain marcasite, chalcopyrite, or other sulfides that cannot be confirmed visually.

Field identification & locations

Look for metallic luster, heavy feel, brittle fracture, and dark streak; pyrite leaves a greenish-black to brown-black streak, unlike gold’s yellow streak. Common settings include hydrothermal veins and sedimentary sulfide deposits worldwide.