Page 255 - Copper and Bronze in Art: Corrosion, Colorants, Getty Museum Conservation, By David Scott

Artifacts decorated Giumlia-Mair and LaNiece (i998) identified niello on a par-
with niello tially gilt silver rhyton in the Civici Musei di Arte e Storia in
Trieste, Italy that has been dated to the Hellenistic period. Two
different niello compositions were found on this ancient Greek drinking vessel shaped in part
like a bull's head: a silver sulfide niello was used to decorate the bull's eyes, nose, and mouth,
while the nostrils were lined with a mixture of silver, copper, and lead sulfides. A second
example of niello decoration is on a stag rhyton in the Ortiz collection in Geneva that is
allegedly from the Black Sea, dating to the fourth century B.C.E. This is one of the earliest
examples of niello reported in the literature, and it was identified by Giumlia-Mair (i998) as a
silver sulfide. Some care must be taken when inferring that black residues in eyes and nostrils
seen on partially cleaned silver objects are the deliberate use of niello because silver or silver-
copper sulfide mixtures are quite common silver corrosion products. Thus it may be that evi­
dence for the use of niello is equivocal in some cases.
I QUESTIONABLE NIELLO IDENTIFICATION Oddy, Bimson, and
LaNiece (i983) note that certain Bronze Age finds from the ancient Greek town of Mycenae that
are often assumed to show the use of niello inlay have not been properly characterized. This was
confirmed by Photos, Jones, and Papadopoulos (1994), who presented semiquantitative surface
analytical data for a black inlay on a Mycenaean bronze dagger in the collections of the Archae­
ological Museum at Patras, Greece. They showed the inlay to be a copper-gold alloy with 5-10%
gold, some silver, and perhaps a trace of tin. The inlay is therefore akin to the Japanese shakudo
(discussed in CHAPTER 2) or to black-surfaced Corinthian bronze alloys; these inlays are
not made of organic resin or niello. The ancient Egyptians were also assumed to have used
niello, but again proof is lacking (Lucas 1962), and use of copper-gold alloys may be more likely
(Craddock and Giumlia-Mair 1993).

Niello chemistry Oddy, Bimson, and LaNiece (1983) also surveyed objects with
niello decoration dating from the first to the thirteenth century
in the collections of the British Museum. Analysis of the niello on a first-century statuette of
Nero from Ipswich showed the presence of cuprite and anilite, Cu 7 S 4 —the only case where
anilite has been identified in this mixture. Other niello analyses revealed chalcocite, Cu 2 S, as
well as a mixture of djurleite, Cu 196 S, and digenite, Cu 176 S, which were identified by powder
X-ray diffraction on a tin bronze from Hod Hill. Niello inlays were used, for example, on the
famous Battersea shield, a gold object of master artisanship in the collections of the British
Museum. The composition of the niello used on these inlaid bronze objects was found to be a
mixed copper-silver sulfide, whereas that of other Roman silver objects was found to be silver
sulfide with no copper addition. The composition of the niello used in the latter pieces was
simply acanthite, Ag 2 S, the same compound found on Byzantine silver objects from the sixth

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