National Geochemical Database: Concentrate

Online link https://mrdata.usgs.gov/ngdb/concentrate/
Description Geochemistry of concentrates from the National Geochemical Database. Primarily inorganic elemental concentrations, most samples are from the continental US and Alaska.
Originators U.S. Geological Survey
Metadata Questions and answers
Schematic map showing sample density in the conterminous US
Schematic map showing sample density in the conterminous US