mineral
Gold-bearing quartz vein in dark host rock
Native gold (Au) with quartz (SiO₂), likely in slate, schist, or altered volcanic rock
AI-generated identification · may be incorrectGray, fine-grained host rock encloses a white-to-translucent quartz-rich vein with brassy yellow metallic particles. Gold is Mohs 2.5–3, extremely malleable, metallic, and dense (specific gravity ~19.3); quartz is Mohs 7 with vitreous luster and no cleavage.
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Physical properties
Gray, fine-grained host rock encloses a white-to-translucent quartz-rich vein with brassy yellow metallic particles. Gold is Mohs 2.5–3, extremely malleable, metallic, and dense (specific gravity ~19.3); quartz is Mohs 7 with vitreous luster and no cleavage.
Formation & geological history
Likely formed when hot hydrothermal fluids deposited quartz and native gold into fractures during mineralization; the specimen’s precise geological age and host rock cannot be determined from the image.
Uses & applications
Gold-bearing specimens are collected, assayed, and potentially processed for precious metal; quartz has limited industrial value here. Market value depends almost entirely on confirmed gold weight and assay results.
Geological facts
The yellow material could be native gold, but brass-colored sulfides such as pyrite or chalcopyrite can look similar. Gold remains yellow in shade and deforms under a point, whereas pyrite commonly crumbles or fractures.
Field identification & locations
Common in hydrothermal veins and orogenic gold districts worldwide, including Australia, Canada, the United States, and South Africa. Test with a specific-gravity/assay method; do not rely on color alone, and avoid destructive acid tests without expertise.
