The native geological formation into which a mineral vein, lode, or igneous mass has been introduced. In mining, it represents the barren waste rock that forms the walls of a stope or the boundaries of a pit. The physical and chemical properties of the country rock determine the mining method, the dilution of the ore, and the stability of the excavations.
Heard on the job
We're getting too much country rock in the muck pile, which is dropping our mill feed grade.