From the Middle Ages on smelting works start securing the success of their production processes by \u201Cassaying\u201D to test which rocks are best suited for processing. The smelting process is simulated on a small scale in the laboratory using crucibles, live coals, and bellows.
Prior to this the ores and all auxiliary materials are pulverized in a mortar, the most important utensil for crushing and powdering hard and brittle substances.