ores

Ores are accumulations of minerals or metals in rocks that could be mined because they contain minerals that are sufficiently economically valuable, sufficiently concentrated, accessible, and extractable. Ore minerals are typically concentrations of oxides, sulfides, silicates, of metals that are not commonly concentrated in the Earth's crust, or are pure "noble" metals such as gold. Ores are mined from the ore body, then processed to extract the metals of interest from from the ore minerals. Not all mineral deposits are ores: mineral deposits are not regarded as ores when they are not economically valuable; or for minerals that are valuable, the deposit is of too low a grade or tonnage, or where extraction is technically impossible. (image : iron ore in banded iron formation, courtesy Siim Sepp)

links: images: close-up: mineral deposits: copper minerals color this vein blue-green, Phoenix gold mine, Idaho Springs