Hallo,
Maybe a bit of a naive suggestion, but could these lead-rich fragments not be
litharge. I’m working on material from ed-Dur, and there we have 3 fragments of
lead-oxide rich ‘slag’. One contains quite a lot of copper, and the ‘bottom’ of
these fragments have a Si- and Ca-rich matrix. They most probably are the
residue of a cupellation process, not to extract silver from lead ore, but
silver from a debased copper-silver alloy, hence the high proportion of copper.
Normally this process was done in sallow crucibles, but apparently it is also
possible do preform in small hearths dug in the ground, as long as the lining is
porous enough and Ca-rich enough to absorb the lead oxide and any other oxides,
leaving behind the silver.
Some references that might help:
HESS, K., HAUPTMANN, A., WRIGHT, H. & WHALLON, R. (1998)
Evidence of fourth millennium BC silver production at Fatmali-Kalecik, East
Anatolia. IN: Metallurgica antiqua: in honour of Hans-Gert Bachmann and Robert
Maddin., (Rehren, Th., Hauptmann, A. & Muhly, J., eds): 57-67. Der Anschnitt,
Beiheft 8. Bochum: Deutsches Bergbau-Museum.
PERNICKA, E., REHREN, TH. & SCHMITT-STRECKER, S. (1998)
Late Uruk silver production by cupellation at Habuba Kabira, Syria. IN:
Metallurgica antiqua: in honour of Hans-Gert Bachmann and Robert Maddin.,
(Rehren, Th., Hauptmann, A. & Muhly, J., eds): 123-134. Der Anschnitt, Beiheft
8. Bochum: Deutsches Bergbau-Museum.
REHREN, TH. & HAUPTMANN, A. (1995)
Silberraffinations-Schlacken aus der CUT (Xanten), Insula 39: Mineralogische
Untersuchung und archäometallurgische Interpretation. IN: Eine Veröffentlichung
des Landschaftsverbandes Rheinland.: 119-137. Xantener Berichte,
Grabung-Forschung-Präsentation 6.
REHREN, TH. & KRAUS, K. (1999)
Cupel and crucible: the refining of debased silver in the Colonia Ulpia Traiana,
Xanten. Journal of Roman Archaeology 12: 263-272.
Greetz,
Parsival
Citeren Anders Söderberg <[log in to unmask]>:
> Dear Adi Behar
>
> > i designated it as slag since it is mostly glassy matrix enriched with Ca
> and Pb, in which copper/bronze drops are embedded/trapped.The lead is only
> confined to the glass matrix. On the bottom side of it (it is flat on one
> side) it is very enriched with quartz, Ca and clay which seemed to undergone
> thermal alterations. Will that not be sufficient to designate it as slag?
>
> Yes, or peraps rather pieces of furnace lining, which is what your
> description reminds me a lot of - glassy matrix on one side and unglazed
> quartz/clay on the other. If so, I would consider is as fragments of a
> technical ceramic material, rather than slag.
>
> Best Regards,
> Anders Söderberg
>
-------------------------------
DELRUE Parsival
PhD student Archaeometallurgy
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GHENT UNIVERSITY
Dept. of Languages and Cultures
of the Near East and North-Africa
St-Pietersplein 6
B-9000 Gent - Belgium
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