The 1981 dissertation of Dennis L. Heskel (1982) on the development of metal technology in Iran and his related publications (Heskel and Lamberg-Karlovsky 1980, 1986), are still three of the most influential treatises on Iranian metallurgy and the social dynamics of metallurgy despite two decades of continued work. Based on his metallographic and chemical analyses of a large corpus of copper-base artefacts and ores from Chalcolithic and Bronze Age levels at Shahr-i Sokhta, Tepe Hissar, Susa, and Tepe Yahya, Heskel argued convincingly against the Marxist models for the development of metallurgy that rely on an inevitable progression of technological stages (e.g. Childe 1944); models that, unfortunately, still exert great influence on archaeometallurgical thought. Heskel, following the seminal work of Cyril Stanley Smith (1965), was also one of the first scholars to note the importance of the copper arsenide deposits of the Anarak-Talmessi region in the early appearance of arsenical copper in Iran and to attempt to demonstrate this connection through technical analysis of the artefacts themselves (see Pigott 1999a: 112-13). Although no archaeological nor geochemical research has yet provided indisputable evidence for the exploitation of this important ore region in prehistory, it is a hypothesis that has remained largely unchallenged. Heskel's most significant contribution, however, was his use of metallographic analysis to understand the techniques of early metalworkers and his integration of these data into a larger socio-cultural context. Although the classic techniques of material science (e.g. optical microscopy) have played a minor role in archaeological explorations of Iran since Mlle. Halm analysed a few metal artefacts from Tepe Giyan and Tepe Sialk in the 1930s (see Heskel and Lamberg-Karlovsky 1986: 207), Heskel was the first to apply these methods to a large sample set (-100 metal objects and ~50 pieces of ore) and make these data the focus of his archaeological research. In recognition of this important contribution to Iranian prehistoric archaeology, we have returned to Heskel's data armed with the last twenty years of archaeological reinterpretation and important new findings from a number of sites. Although Heskel's metallographic research is exempl ry, it suffers from two unavoidable problems. First, the stratigraphy of Tepe Yahya, a small (4 ha) site in the Soghun Valley -220 km. south of Kerman that was the centrepiece of Heskel's study due to its long C'4-dated chronological span, had not been interpreted fully by the time he finished his dissertation. Thus, many of the artefacts' contexts were misconstrued. S cond, the spectrographic analysis of his samples was only semi-quantitative, most notably in the detection of arsenic (see Heskel 1982: 284-85). Indeed, recent analyses of the Yahya collection using an inductivelycoupled plasma mass spectrometer (ICP-MS) and electron microprobes have shown that the levels of arsenic he reported are consistently too low by a factor of 1-3wt% (see Thornton 2001: 72-74). Despite the problems, Heskel's work should not be ignored and will here, once again, serve as the foundation for a paper on the development of metallurgy in prehistoric Southeastern Iran as seen from Tepe Yahya.