Egyptian ivories

Recently I have been given two rather extraordinary ivories which I
believe likely date from the first millennium and were likely made
in Egypt.  The pieces are carvings of animals, one perhaps a variety
of ibex, the other a weird cross between rabbit and cow.  Of
interest is the fact that the two animals (which are badly
deteriorated) are covered with an ethnographic accretion which I've
analyzed with XRF. The accretion has a resin component but
non-organic elements include iron (in greatest proportion), copper
and calcium.  Under the microscope, charcoal is visible, as are tiny
pigment spots, blue and yellow, red and yellow.  My assumption is
the greater presence of iron oxides, but was wondering if anyone
knows how long the iron from hemoglobin would survive in burial. The
accretion does not appear to be a burial accretion, and I'm curious
to know if there are others out there who have come across such
pieces and have had them analyzed.

Of addition interest is the fact that the horns/ears of the animals
are cast in bronze and inserted into?the ivory, and there is
evidence that the tail of one (which is missing) was also made of
bronze or?some other copper-based alloy, this assumed because of the
green staining of the ivory around the hole where the tail was
originally inserted.  What is most mystifying however, is the fact
that both animals have bronze rings, tightly fit around the ankles
of the animals.  For the life of me, I can't figure out how the
rings were cast on? to the ivory.  I haven't analyzed the bronze
yet, perhaps it's a nearly pure copper which would make more sense
technically since copper can be worked cold, though still a
difficult process to work copper into a ring around ivory with no
join apparent.

Ah, so my question is this: has anyone encountered pieces of this
type? I've had a curator of some renown look at photos and she
thinks they were probably made in Egypt for an Assyrian tomb.  As a
conservator, of greatest concern, is determining for certain that
the accretions were deliberately applied, as ritual material, rather
than burial accretion from proximity to an organic resinous material
containing pigment. The accretions occlude much of the delicate
carving of the? ivory and I'm inclined to remove some of it to
reveal the beauty of the carving, but not all, in case there is
important ethnographic information contained in the accretion.

Susan White
White Conservation Services


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                  Conservation DistList Instance 23:2
                  Distributed: Thursday, May 28, 2009
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