The medieval crucibles from two localities – Brno, Mečová Street and Jihlava Staré Hory were studied in order to determine the nature of raw materials, metals and the technological aspects of their production and use. The glass phases of all crucibles contain new formed minerals which grew rapidly during cooling. Cu rich ore or copper were probably melted in crucibles from Brno and in case of Jihlava Staré Hory crucibles were used for melting of Pb rich argentiferous ore
