Ulvöspinel-bearing iron slags of Hellenistic age from near the Rosen copper mine, Eastern Srednogorie, Bulgaria.
W E Sharp and Radoslav Nakov.
Historical Metallurgy Journal Volume 50, Issue 1
A mineralogical study of slag of the Hellenistic period from near Cape Atiya on the Black Sea coast between Burgas and Sozopol has shown that these are iron slags consisting mainly of ulvöspinel, titanowüstite, kirschsteinite, and kalsilite. The abundant presence of ulvöspinel in the slag and its high vanadium content, suggests that the iron ore employed contained magnetite mixed with titanite derived from the disintegration by weathering of the monzonites and syenites of the Rosen pluton. The dominance of kirschsteinite over fayalite in the slag, along with rounded grains of magnesiochromite and the presence of zirconium in the slag, suggests the ore was a locally-derived shelly beach sand.