mineral

Probable weathered sulfide-bearing rock

Indeterminate; possibly pyrite- or chalcopyrite-bearing matrix

AI-generated identification · may be incorrect

Small irregular specimen with dull bronze-gold metallic grains in a dark, earthy matrix; likely hardness 3–6 depending on mineral content, with uneven fracture and no visible crystal form. The gold color may be tarnished pyrite or chalcopyrite rather than native gold.

Identified August 26, 2026More mineral →

Explore Probable weathered sulfide-bearing rock in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Likely formed in a hydrothermal vein or sulfide-rich metamorphic/igneous environment; precise age and locality cannot be determined from the photograph.

Uses & applications

Primarily a collecting specimen; sulfide ores can be sources of sulfur, copper, or other metals, but this fragment is not suitable for commercial use based on appearance alone.

Geological facts

Pyrite commonly forms brassy metallic crystals and leaves a dark streak, while chalcopyrite is softer and often develops iridescent tarnish. Native gold is much denser, softer, and usually more distinctly yellow.

Field identification & locations

Test with a streak plate, hardness pick, magnet, and specific-gravity measurement; do not assume it is gold from color alone. Common possibilities occur in hydrothermal veins and mining districts worldwide.