The Determination of Trace Elements in Ancient Silver Objects by Thermal Neutron Activation Analysis: A Preliminary Report

Abstract

Thermal neutron activation analysis has proved to be a successful method to determine three of the four principal components, i. e., silver, copper and gold, in ancient silver. The fourth element usually found in sizable concentrations, lead, cannot be determined readily by this method. Sometimes for smaller objects such as coins, the analysis can be performed without the removal of any material through activation and counting of the entire object. In most cases, however, the objects are too large to be so analyzed conveniently, hence sampling is required. For that purpose, small drillings (0.2-1 mg. ) are preferable. If drilling is not permissible, small samples (10-200 pig.) can be obtained by rubbing pure quartz plates or tubes against the surface of the object to be analyzed. Many ancient silver coins and other objects have been analyzed using these techniques. For details of these experiments, one is referred to the literature.1'2