The sources of lead and silver for Bronze Age artifacts, archaic coins etc. in the Greek world are not known with any certainty except in the case of Laurion, Attica. This article discusses briefly the nature and sources of our knowledge, the occurrence of silver and lead in nature, the lead isotope method and its application to tracing ancient mines, the date of first working of the Laurion mines, and new information about the ancient mines of Siphnos.