scheelite or calcium tungstate on white background. metallic mineral.

associated background black bloom calcium carbon carbonate cassiterite coal collection commonly country crystal dioxide endmember ferberite fossil found fuel geology gold granite gray hard heavy hydrozincite igneous intermediate iron isolated macro major manganese marionite material metal metallic metamorphic mineral minerals natural nature object ore oxide piece primary principal pyrite raw rock rocks rough scheelite series set solid solution stone stones texture tinstone tungstate tungsten white wolframite worlds zinc