Copper Alloy and Raw Copper Waste: Descriptions (JPN)

Extract

Analyses of the following items are given in microfiche Table 6, where details of sample and context numbers are also listed. See also full catalogue of metallurgical debris in Table 2.

44. Irregular flat piece of bronze, 13x12 mm; as cast medium tin bronze; corroded away; dendrite arm spacing = 30 40μ, suggesting a moderate cooling rate; interdendritic distribution of sulphide clusters, all basically Cu₂S, although some contain a few percent iron; massive surface corrosion with islands of α and δ; fragments of charcoal and small areas of typical melting slag adhering, some possibly having originally floated on the surface of a melt. It is reasonable to suppose that this piece could have been the residue left in a crucible after a pour and had set there and been knocked out later, with charcoal and dross still embedded in the metal. See also analysis of sulphide inclusions in microfiche Table 7.