Where copper has been recorded in California

Found alongside

• Copper

  Mohs 2.5–3. Native copper is soft and turns green as it weathers. Mindat

  4,116 sites

• Gold

  Mohs 2.5–3. Soft, heavy and bright yellow; it doesn’t tarnish. Mindat

  2,026 sites

• Silver

  Mohs 2.5–3. Native silver tarnishes black. Mindat

  1,649 sites

• Quartz

  Mohs 7. Six-sided points; smoky quartz is NH’s state gem. Mindat

  646 sites

• Pyrite

  Mohs 6–6.5. Brassy “fool’s gold,” often cubic. Mindat

  644 sites

• Galena

  Mohs 2.5–2.75. Heavy, silvery lead ore that breaks into cubes. Mindat

  259 sites

Counts are sites whose USGS record mentions the mineral or commodity. Hardness from Mindat.

How we built this page: we counted named sites in the USGS Mineral Resources Data System (MRDS) for this area, left out sand, gravel, crushed stone, clay pits and unnamed sites, grouped them by Census county, and linked every site to its USGS record. We did not visit these sites, and MRDS does not tell you who owns the land or whether collecting is allowed.

Source: USGS Mineral Resources Data System (MRDS). USGS ceased systematic updates to MRDS around 2011, so status and details may be out of date. Each site links to its USGS record.

Updated October 2026