Thirteenth century Venetian grossi were prototypes for early Serbian silver coins. Close copying apparently was intended to facilitate the export of silver in the form of coinage, and did lead to the political and economic development of the region of Bosnia and Serbia. However, Serbian copies were struck at a reduced standard, leading do various exchange ratios. By the early 14th century, the Serbian issues were perhaps 80% pure. A compositional study reported in this article was intended first to chart the debasement of the alloy and second to test whether the trace gold in the silver could be used to identify sources. Two techniques of neutron activation were employed. One technique involved a very short irradiation for short-lived isotopes of silver. A second involved a longer, high flux irradiation of a very small sample to determine gold, silver, and copper. Discrepancies in silver determinations between the two techniques may reflect local variations in the alloy. Two distinct episodes of reduction in the silver content of the Serbian coins are identified. The two episodes are separated by about 50 years, and it is difficult to document changes within that span. Gold content holds some potential for source studies, but more analyses are required. A catalogue of analyses is provided.