The DMS process relies on a medium of specific density (specific gravity) that is between the density of the minerals targeted for separation. The form of the medium has changed throughout the years, but today is almost exclusively ferromagnetic powders such .
Rocks with large concentrations of minerals, are called ores. Mining depends on finding good quality ore, preferably within a small area. The next step is to get the rocks which contain the mineral out of the ground. Once the ore is on the surface, the process of getting the mineral you want out of the rock can start.