Page 229 - Copper and Bronze in Art: Corrosion, Colorants, Getty Museum Conservation, By David Scott

P L A T E 7 1 Statuette of Roma or Virtus, Roman,
4 0 - 6 8 C E . Bronze, H : 3 3 . I cm. This anonymous Roman
work is thought to be part of group comprising this fig­
ure, a relief fragment of two men (see P L A T E 73) , and Ceres
or Juno, all at the J. Paul Getty Museum, and a winged
Nike (see P L A T E 74 ) at the Cleveland Museum of Art. The
patina of the Roma is rich in tin oxides, compared with
the composition of the metal, and has a matte luster with
surface mottling, with enrichment in iron also evident.
Malibu, J. Paul Getty Museum ( 8 4 . A B . 6 7 I ) .

P L A T E 7 2 Detail from the reverse of the Roma shown
in P L A T E 71 , revealing an unusual hexagonal network
structure within the corrosion crust. There is no simple
explanation for the presence of these hexagonal
structures, which do not correspond to any obvious
metallographic features in the bronze microstructure
6
(magnification χ 2).
P L A T E 7 3 Relief Fragment of Two Men (the "Togati
bronze"), Roman, 4 0 - 6 8 C . E . Bronze, H : 2 6 cm;
1
w: 3.8 cm. This tin bronze, which may have originally
belonged to a frieze, has an interesting iron-stained patina
that is rich in tin oxides and also includes fibrous mala­
chite, traces of terra-cotta tile, and pustules of corrosion.
Malibu, J. Paul Getty Museum ( 8 5 . A B . 1 0 9 ) .

P L A T E 7 4 Victory with Cornucopia (winged Nike),
Roman, 4 0 - 6 8 C . E . Bronze, H : 4 2 cm. The patina on
this figure is similar to that of the two men shown in
P L A T E 73 , with its matte surface, iron staining, enrich­
ment in tin oxides, and the presence of fibrous malachite
crystals. Cleveland Museum of Art, Leonard C. Hanna, Jr.
Fund (1984.25) .

P L A T E 7 5 Low-power photomicrograph of surface corro­
sion on the two men shown in P L A T E 73 . Preservation of
71 pseudomorphic remnants of the original dendritic struc­
ture can be seen in the dark green globular fragments,
which contain substantial amounts of both copper and
2
lead salts (magnification χ 1).
P L A T E 7 6 Photomicrograph of a sample from the bronze
statuette of Roma shown in P L A T E 71 , illustrating cross
section of one of the hexagonal features (see P L A T E 72) .
The sample, taken from the interior surface of the figure,
was lightly etched in alcoholic ferric chloride, revealing
a microstructure with an equiaxed annealed cast mor­
phology to the alpha+delta eutectoid phase and a fairly
typical corrosion crust penetrating into the matrix
(magnification χ352) .

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