Egyptian faience

In my studio for restoration is a (broken) ushabti or shabti, which
is a small Egyptian faience statuette which was placed in a tomb to
accompany the deceased. The original sherd is a bright turquoise
colour but almost the entire surface of the figure is now unevenly
discoloured, with many yellow/orange/brown stains, although these
are less on the rear. Under the foot they are even darker, a
brownish-black colour. The--now elderly--owners asked for the
ushabti to be bonded and filled, but also that it be thoroughly
cleaned, restoring it to the colour they remember it having
originally i.e. the bright blue-green of the sherd.

Assuming from this information that the stains may be from something
like nicotine, I first bonded the two halves (Paraloid B 72) then
proceeded to steam clean the figure. Although this removed quite
some surface dirt it made no inroads on the yellow discolorations.
Neither did cleaning with non-ionic detergent, and tests with
acetone and xylene were equally ineffective. The discolorations now
look much more like iron stains to me and give the impression of
being to be much older, even from the days in the tomb.

Since tinted fillings are designed to blend in with the background
colour, before I proceed to this next phase I first need to know
whether the staining is irreversible or whether there is something
more I could undertake. Does anyone have experience with this
problem?

Lindsey Bogle
De Porselein Studio
Maasdijk 423
4264 AS  VEEN
Netherlands
+31 416 696807
Fax: +31 416 696856


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                  Conservation DistList Instance 19:30
                Distributed: Thursday, December 15, 2005
                       Message Id: cdl-19-30-018
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