A channel, tunnel, gate or opening purpose-built for moving ore
A channel, tunnel, gate or opening purpose-built for moving ore
A silver-gray, metallic element. Symbol, Co
An isometric metallic mineral, Cr
Large grains of Gold
The metamorphic processes which form coal
A carbonaceous rock formed through the alteration of plant remains, used as fuel
A compacted mass of mineral matter
A hardened rock-like mixture of sand or gravel, water, and Portland cement
A processing machine that assists in the separation of particles by weight and density
The heaviest collected particles or minerals reduced from a larger unclassed volume