What is hard rock mining?
1 Answer
Essentially; its mining in igneous or metamorphic terrains and involves base metals for the most part.
Explanation:
Hard rock is geological euphemism for those who deal with igneous or metamorphic rocks - which, not surprisingly are very hard when you hit them with a hammer! In fact, you need a special kind of heavy geological hammer. See pic 1 - quite heavy and no pointy end.
Soft rock refers to geological studies undertaken in sedimentary rocks, which as the name implies, tend to be softer to the hammer blow! They are the usual geologists hammer with a sharp pic at the end See pic 2
So, hard rock mining tends to be in metamorphic or igneous Pre-Cambrian shield terrains of the world. Base metals such as copper, zinc, iron, nickel, or lead are often the minerals of interest. 
The mining tools for hard rock mining also tend to be more costly, as diamond or tungsten carbide bits are needed for drilling and blasting.
