Adi-
Tom Fenn and I have very similar material from the site of Marandet, Niger,
from the period of the trans-Saharan caravan trade. These are crucibles of
very coarse clay, containing large grains of quartz, in which heavily-leaded
copper (up to 20% Pb) has been melted in an evidently oxidizing environment.
The molten lead oxide formed by surface oxidation has attacked the crucible
walls, providing just the kind of transition that you describe. In our case
the glass contains dendrites of cuprite, which colour the glass bright red.
David Killick
Associate Professor
Department of Anthropology
University of Arizona
Tucson, AZ 85721-0030
U.S.A.
phone (520) 621-8685
fax (520) 621-2088
-----Original Message-----
From: Arch-Metals Group [mailto:[log in to unmask]] On Behalf Of
Anders S öderberg
Sent: Tuesday, November 07, 2006 8:46 AM
To: [log in to unmask]
Subject: Re: AW: Lead production in the Roman period
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
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