metamorphic
Weathered sulfide-bearing metamorphic rock (likely pyrite- or chalcopyrite-rich schist)
Quartz–mica schist with iron sulfides; possible pyrite (FeS₂) and chalcopyrite (CuFeS₂)
AI-generated identification · may be incorrectHardness is approximately 3–6 overall, with brassy yellow metallic grains, gray matrix, and irregular fracture; likely foliated, though weathering obscures the fabric. Yellow-brown surface staining suggests oxidation to iron oxides/hydroxides.
Identified More metamorphic →
Explore Weathered sulfide-bearing metamorphic rock (likely pyrite- or chalcopyrite-rich schist) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness is approximately 3–6 overall, with brassy yellow metallic grains, gray matrix, and irregular fracture; likely foliated, though weathering obscures the fabric. Yellow-brown surface staining suggests oxidation to iron oxides/hydroxides.
Formation & geological history
Probably formed when a clay- or volcanic-rich sediment was metamorphosed and sulfide minerals crystallized during hydrothermal or metamorphic alteration. The exact geological age cannot be determined from the image.
Uses & applications
Primarily a teaching or collecting specimen; sulfide-bearing rocks can be indicators of copper, gold, or other ore deposits, but this fragment is not demonstrably ore-grade.
Geological facts
Pyrite is commonly called “fool’s gold,” while chalcopyrite is a major copper ore and often tarnishes to iridescent colors. Sulfide oxidation can produce rusty coatings and acidic drainage.
Field identification & locations
Look for metallic brassy grains, streak, density, and possible foliation; pyrite has a dark greenish-black streak, whereas chalcopyrite is softer and often iridescent. Common in hydrothermal veins and metamorphosed volcanic or sedimentary terrains.
More like this
