Parsival,

That was exactly my point at the beginning of this discussion - to not rule other metals/alloys out in favour of Cu or Cu-alloys.

It's a fact that cupellation is not only connected to mining/production, but also to silver refining connected to re-cycling. REHREN, TH. & KRAUS, K. (1999), "Cupel and crucible: the refining of debased silver in the Colonia Ulpia Traiana" deals with this subject in a good and clearifying way, and so does J Bayley in several papers.

We have found residues from large scale refining in Sweden as well, in connection with late Viking Age production of silver armlets/currency and also possibly connected to medieval minting. In those cases though, we are dealing with bone ash hearth lining (see http://members.chello.se/vikingbronze/silverworkshop.pdf )

The fact that the mentioned Roman/Israeli pieces contains a lot of Ca, did lead my thoughts towards lime or marl as a hearth lining material which I suppose would be an advantage in this process.

Anders Söderberg


> 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
>  [log in to unmask]
> 
> GHENT UNIVERSITY
>  Dept. of Languages and Cultures
>  of the Near East and North-Africa
>  St-Pietersplein 6
>  B-9000 Gent - Belgium
>