The X-ray spectrometer method as an archaeological tool is discussed with special reference to its limitations as a chemical analytical instrument. Qualitative results are presented for six North American copper samples, one European trade brass, and nine artifacts from the Great Lakes region. From this pilot study it is concluded that the most fruitful results in the problem of the determination of provenance of copper artifacts will be obtained from semi-quantitative optical spectographic analyses of carefully collected artifacts and raw materials. The largest inherent error in this problem is that of meaningful sampling techniques. The only recourse is to treat such chemical data statistically and determine the probabilities that given specimens came from the various possible sources.