Neutron activation measurements for Eu, Sc, Cs, Th, Ta and Fe on 6 samples of pottery and rock by the Hebrew University and the Lawrence Berkeley Laboratory have been compared. The average disagreement BM: 6181, exclusive of counting errors was 1.1%. The practical importance of this study to archaeology is that data taken on source materials in one laboratory can be used by the other. Methods of determining the consistency of measurements within a laboratory and sources of errors are also discussed. -- AATA