| Polarized light microscopy (PLM) together with scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS) were used to investigate the mining and mineral processing remains from a recently discovered archaeological site in the Taurus Mountains of southeastern Anatolia, Turkey. The ancient mine, Kestel, and miner's village, Goltepe, are believed to be one of the rare sources of tin during the Early Bronze Age, i.e., the late fourth to early third millennium BC, coincident with the earliest occurrence of bronze metal artifacts in Asia Minor.; This thesis shows how prehistoric miners at the Kestel mine were using the magnetic properties of black iron oxide to accomplish the difficult separation of cassiterite (tin oxide) from extremely low-grade cassiterite ores. Excavations at the site of Goltepe, dating to the third millennium BC, have yielded specular hematite ore nodules containing a few percent, or less, of cassiterite and a sequence of processed, ground, and separated minerals. Laboratory experiments showed that reduction at temperatures as low as 700-900{dollar}spcirc{dollar}C could convert red hematite to the much more easily crushable black magnetite; a reduction that could readily be accomplished in bowl furnaces. On panning the magnetite, the magnetic oxide clumped together effectively to yield almost complete separation from the cassiterite ore; a separation which, without the magnetic property of the oxide, could not have been accomplished due to the similar densities of these minerals.; The deliberate production of magnetite explains: the design of crucible bowl furnaces; the vast quantities of ground stone tools; the large amount of residual magnetic oxide; the presence of fine powders and small particle diameters which were necessary for the isolation of tin ore and the magnetic separation; and establishes Kestel/Goltepe as a viable cassiterite production site. |
