Among other materials, fahlores were used in the Bronze Age copper ore smelting process. These contain, apart from sulfur, arsenic and antimony. Therefore, these elements can be found in Bronze Age copper casting ingots or artifacts. In order to study the behavior of Sb more closely, two copper alloys containing 10 and 30 wt. % Sb were melted and subjected to a metallographic examination. On the one hand, microstructures with copper dendrites and homogeneous interdendritic areas primarily composed of intermetallic phase could be found. On the other hand, at higher Sb concentrations, first Cu 3 Sb precipitated which, in turn, transformed to Cu 10 Sb 3 upon cooling. The crystals in these microstructures were characterized by numerous parallel cracks. No further phases were observed by XRD.