mineral

Pyrite-bearing quartz rock

Quartz (SiO₂) with pyrite (FeS₂), possibly in a metamorphic host rock

AI-generated identification · may be incorrect

Gray, granular to crystalline matrix with brassy metallic pyrite flecks; quartz hardness 7 and pyrite 6–6.5 Mohs. Pyrite commonly forms cubic crystals, while quartz is vitreous and lacks prominent cleavage; exact composition cannot be confirmed from the photo alone.

Identified September 3, 2026More mineral →

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Physical properties

Formation & geological history

Likely formed from hydrothermal mineral-rich fluids filling fractures or replacing rock, commonly during metamorphism. Its geological age depends on locality and cannot be determined visually.

Uses & applications

Mostly a collector specimen; pyrite is historically used for sulfur and sulfuric-acid production, while quartz has major industrial uses in glass, electronics, and abrasives.

Geological facts

Pyrite is called “fool’s gold,” but it is harder and more brittle than gold and commonly tarnishes. A streak test produces a greenish-black to brownish-black streak, unlike gold’s yellow streak.

Field identification & locations

Look for metallic brassy grains, angular fracture, and possible cubic forms; quartz appears gray-white and glassy. Common settings include hydrothermal veins and metamorphic rocks worldwide; avoid relying on color alone because chalcopyrite can look similar.