Samples of casting core material, from the bronze statue Jüngling vom Magdalensberg (Renaissance period), from some bronze figures of the Leopoldsbrunnen (1622-1629/30) in Innsbruck and from a Roman bronze statuette (Tanzender Satyr, Kunsthistorisches Museum Wien, Antikensammlung) were studied by means of petrographical and mineralogical techniques. Thin section analyses show that the casting core material of the bronze figures of the Leopoldsbrunnen (Innsbruck, Tyrol) and the Jüngling vom Magdalensberg were originally composed of loam or marl, mixed with organic material (probably dung), which were altered to variable extents due to processes during and after casting. Both groups of samples show slight but significant differences in their petrographical and mineralogical composition. The results of heavy mineral analyses and the determination of the rock fragments, visible in the thin sections, show that the material of both groups is very similar to sediments found near to the surface within the Alpine region (mainly metamorphic rock fragments and minerals, together with carbonates). The sample of the Roman bronze statuette is composed of fine grained sand cemented with a black groundmass which is rich in carbon and organic matter. The results of the thin section and heavy mineral analyses showed that an Alpine provenance (and therefore also the region of Carnuntum, Pannonia Superior (40 km east of Vienna), where this object has been found) can be excluded. Significant is the occurrence of volcanic rock fragments and a heavy mineral composition rich in augite. A source from a region influenced by recent volcanism seems to be probable. For more accurate conclusions and detailed comparisons, the study of various casting core materials, including material of well known provenance, will be necessary.