* Argentite: Ag2S for production of silver
* Chromite: (Fe, Mg)Cr2O4 for production of chromium
* Gold: Au, typically associated with quartz or as placer deposits
* Uraninite (pitchblende): UO2 for production of metallic uranium
I can't seem to find anymore. :'(
Could somebody help get the ball rolling.
platinum
Iridium
Titanium