Slag from an ancient copper smelter at Timna Israel

This paper presents an examination of slag from an ancient copper smelter near Timna, Israel, by electron microprobe analysis, x-ray diffraction and x-ray fluorescence. The slag consists essentially of fayalitic olivine (ca. 20%), ferro-hedenbergite (ca. 55%) and a glassy matrix material (ca. 25%). The origin of the slag and the nature of the smelting process is interpreted on the basis of the simple ternary CaO-FeO-SiO 2 system. Textural and compositional features of copper-iron pellets in the slag combined with the silicate composition of the slag suggest a process which involved rapid cooling from a minimum fusion temperature of 13501400° C. This evidence is in keeping with smelting under reducing conditions in open sandstone depressions. (See also 13-1225. ) -- AATA