ANCIENT TIN SMELTING AT MT. CER, SERBIA: CHEMICAL AND MINERALOGICAL EVIDENCE FROM CRUCIBLE SHERDS

The source(s) of tin for Aegean bronze is undetermined but several small Bronze Age tin mines have been documented in the circum-Aegean region. One such deposit is Mt. Cer in west Serbia. Although no direct evidence of mining has been discovered, Bronze Age habitation sites correlate with the location of the highest grade placer deposits. Approximately a dozen possible crucible fragments have been uncovered from the Spasovine site adjacent to the Milinska River. Chemical and mineralogical characteristics of one such ceramic sherd with a 3 mm thick vitreous coating on the outer surface is consistent with on-site smelting of placer tin ore mined from the slopes of Mt. Cer. The silica-rich glass contains silicified ash up to 10μm in diameter beside which micro-fractures and pores contain metallic tin, and less commonly, secondary tin chloride phases. In addition, the glass contains micro-inclusions (<20μm) of refractory minerals: zircon, monazite, and ilmenite are the most abundant; rutile and xenotime are relatively common; rare scheelite and brannerite are present as well. All of these heavy minerals have been identified in the heavy mineral fraction of cassiterite-bearing river sands in the adjacent cassiterite-bearing Miliniska River. Elevated Th concentration is characteristic of both the glass and the river sand. Although the age of the fragment cannot be constrained typologically, vast majority of pottery fragments from Spasovine are Late Bronze Age in date. Thus the metallurgical sherd is likely Bronze Age as well, but the possibility remains that it could be later.