Nowadays, metallurgy is described as the technological know-how of metals, but up to the 18th century, it only involved the practices of metallurgy, which includes the traditional techniques of smelting, melting, and working of metals. The spread of those practices was not even throughout the world but varied according to the ability of civilizations to invent new and take benefits of known techniques.
When inquiring about the foundation of metallurgy, it’s critical to explore certain everyday techniques utilized in lithic societies, because the utilization of metals arose out of the studies of lithic peoples with metallic materials. The extensive utilization of red oxide of iron in ritual and funerary practice is documented over a wide place from the earliest times. Neolithic people also decorated walls with it, and at Eridu and Susa pieces of hematite have been used for burnished pottery by approximately 4000 BC. The greens and blues of copper minerals would appeal, and their use as cosmetics in Egypt and Mesopotamia is properly attested. In Crete, small pieces of azurite have been observed all through a habitation layer dated to c. 6000 BC.
There is little doubt that when the neolithic pottery stage was reached, green minerals were used for adorning pottery; their instability would soon be discovered for, in contrast to the red oxides of iron, copper-base minerals turn black when heated under oxidizing conditions. The effect of reducing conditions in producing globules of metallic lead during the firing of lead glazes is well known, and one wonders whether or not smelting could have been found this way. There is isn’t any evidence for this, but the fact that enclosed kilns, in which sufficiently reducing conditions would be possible, were not known until the Copper Age might suggest that such an accident was responsible for the origin of copper smelting.
- R. F. Tylecote (1977), A History of Metallurgy, British Corrosion Journal, 12:3, 137-140