Copper objects first circulated on the Greek mainland during the fifth millennium BC and shortly after in the islands of the southern Aegean (Zachos 2007). The earliest metalwork of Late Neolithic date comprised small objects such as awls, beads, and bracelets. Metal use gradually expanded during the Chalcolithic stage that followed, with production of larger items such as axeheads. There are parallels with the development of early metallurgy in the Balkans, however there was much less copper in circulation. This may be explained by the absence of early copper mines comparable to Rudna Glava or Ai Bunar in either Greece or the Aegean islands. The use of metal in the Aegean expanded significantly during the third millennium BC, with the emergence of a flourishing culture that had extensive seafaring contacts (Renfrew 1972). The importance of maritime trade in this region dates from the Neolithic when the island of Melos was a major source of obsidian across the east Mediterranean. Lead isotope analysis confirms that the copper, lead, and silver used by the Cycladic culture of the Early Bronze Age came from ore sources on many of those islands (Stos-Gale 1989). These metals were traded widely across the Aegean, with supply also into mainland Greece. While no copper mines have been identified, lead/silver workings of this period are recorded at Lavrion and at Ayios Sostis on Siphnos (Wagner et al. 1980). There are numerous deposits of copper ore and other metals in mainland Greece. No prehistoric copper mines have been identified; however, the potential has been examined by lead isotope analysis. An examination of various ore deposits in northern Greece, including examples in Thrace and eastern Macedonia, Thasos, the Pangeon Mountains, and Chalkidki did not reveal any likely sources of copper in prehistory. Samples were also taken in east-central Greece, from mineralization in the Othrys Mountains where there are several indications of ancient mining. Radiocarbon dates indicate copper mining at various locations there during the first millennium BC (Gale and Stos-Gale 2002: table 3).