Neutron tomography data on high-Pb antique bronze coins indicated that two different copper alloy phases are formed during the casting process. We propose to use GEM for studying the phase composition of the bronze alloys, for detecting the presence and distribution of the Pb phase, and for determining texture and microstructure parameters of the phases, non-destructively. 20 original Greek bronze coins from the Kunsthistorisches Museum Vienna will be compared to self-cast replicas to clarify the casting techniques (vertical or horizontal) and to differentiate between either only-cast or cast-and-minted objects. The phase and texture data are important to interpret the tomography data and to unravel the technology of antique coin production.