mineral
Gold-bearing quartz vein in dark host rock
Native gold (Au) with quartz (SiO₂), likely in a mafic or metamorphic host
AI-generated identification · may be incorrectVisible yellow metallic native gold occurs as irregular flakes or veinlets in a dark, fine-grained matrix. Gold has Mohs hardness 2.5–3, very high density (~19.3), bright metallic luster, and malleability; quartz is hardness 7 and vitreous.
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Physical properties
Visible yellow metallic native gold occurs as irregular flakes or veinlets in a dark, fine-grained matrix. Gold has Mohs hardness 2.5–3, very high density (~19.3), bright metallic luster, and malleability; quartz is hardness 7 and vitreous.
Formation & geological history
Hydrothermal fluids deposited gold and quartz in fractures, commonly during Precambrian to younger orogenic mineralization; the exact age and host cannot be determined from the photograph.
Uses & applications
Primarily a collectible or assay specimen; native gold is used in jewelry, electronics, dentistry, and investment, while quartz has industrial and ornamental uses.
Geological facts
Gold is notably malleable and will flatten rather than crumble when pressed; true gold is not attracted to a magnet and does not tarnish readily.
Field identification & locations
Commonly found in quartz veins and greenstone belts, especially in Australia, Canada, California, Alaska, and South Africa. A streak, density test, magnet test, and professional assay help distinguish gold from pyrite or mica.
