Investigated are the raw materials and waste products of iron smelting operations as well as analyses of iron artifacts from Thasos and the East Macedonian mainland. The methods of examination involved elemental analysis by x-ray fluorescence and atomic absorption spectrometry of ores and slags, and chemical analysis of mineralogical phases in slags by electron probe microanalysis (EPMA). The purpose of this study is to establish the type of iron ore sources used in particular periods, as well as to shed light on aspects of extractive iron metallurgy, namely furnace conditions. -- AATA