De metallorum ortu & causis

experts in nature, it becomes a metal, yet it is not led by the hammer. Indeed it is fragile. Therefore, when melted in crucibles and purified in the manner of all metals, it is usually called icy tin stannum glaciale a term for bismuth or perhaps a brittle tin alloy by the tin-smiths because it breaks like ice. It is also called the Regulus of Antimony Antimonii regulus the metallic form of antimony by the charcoal-burners, who use it very frequently. Stones, truly, although they are fossil bodies and some of these melt, are nevertheless excluded from the category of metals. For melted metals, once the heat is cooled and extinguished, return again to their native hardness and proper form. But melted stones (I speak of meltable ones, for some cannot be melted), although they are returned to their inherent hardness, they nevertheless lose their natural form. Furthermore, metal is divided in various ways by historians of subterranean and fossil things. For into eight differen-