Where magnetite has been recorded in California

Found alongside

• Magnetite

  Mohs 5.5–6.5. Black and strongly magnetic. Mindat

  144 sites

• Pyrite

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

  47 sites

• Gold

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

  40 sites

• Quartz

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

  36 sites

• Copper

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

  33 sites

• Silver

  Mohs 2.5–3. Native silver tarnishes black. Mindat

  29 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 USGS ceased systematic updates to MRDS around 2011, so status and details may be out of date.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