metamorphic

Likely pyrite-bearing metamorphic rock

Quartz–mica schist or phyllite with disseminated pyrite (FeS₂)

AI-generated identification · may be incorrect

Dark gray-green, foliated, and sparkly with brassy metallic patches; likely hardness 2–6 depending on minerals, with uneven fracture and moderate-to-high density. The brassy grains may be pyrite, but image resolution prevents confident mineral identification.

Identified September 22, 2026More metamorphic →

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Physical properties

Formation & geological history

Probably formed when clay-rich sediment was buried, heated, and compressed during regional metamorphism; its exact geological age and locality cannot be determined from the photograph.

Uses & applications

Primarily a teaching or collecting specimen; pyrite-bearing schist may be used locally as decorative stone, but it is generally unsuitable for high-value jewelry or construction.

Geological facts

Pyrite is iron sulfide, FeS₂, commonly called “fool’s gold.” Unlike gold, it is brittle, commonly forms cubic crystals, and can produce a dark streak rather than a yellow metallic streak.

Field identification & locations

Look for planar foliation, sparkly mica, and brassy grains; a streak test, hardness test, magnet test, and acid reaction would help distinguish pyrite-bearing schist from sulfide-rich ore or slag. Similar rocks occur in metamorphic belts worldwide.