An Etymological Dictionary of the German Language/Annotated/Erz
Erz, neuter, ‘ore, metal, brass, bronze,’ from the equivalent Middle High German ęrze, arze, Old High German ęrizzi, aruzzi, aruz, neuter; an obscure word, which is unknown to the other Teutonic dialects; probably borrowed under the form azuti, arwuti?. In Gothic ais, Anglo-Saxon âr, English ore, Old High German and Middle High German êr, ‘bronze,’ whence the Old High German and Middle High German adjective êrîn, Modern High German ehern; these are primitively cognate with Latin aes, ‘bronze,’ and Sanscrit ayas, ‘metal, iron.’