Page 191 - Copper and Bronze in Art: Corrosion, Colorants, Getty Museum Conservation, By David Scott

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P L A T E 6 Photomicrograph of a marine organism preserved on corroded copper.
The preservation of a variety of organic materials on copper or bronze objects is
not unusual, due to the biocidal action of copper ions (magnification χ 8).
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P L A T E 7 Photomicrographs of four corroded bronze objects: A , polished and
etched section of a bronze ceremonial ax, ca. 500 B . C . E . , from the Luristan region
of Iran, showing redeposited copper in corroded matrix of alpha, copper-rich den­
drites and alpha+delta eutectoid phase, which was replaced with the redeposited
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Β
copper during corrosion (magnification χ 17); , polished section of an Iranian
toggle pin, dated to the Middle Bronze Age, showing curved boundary representing
the original surface of the object within the corrosion crust (magnification χ 122);
c, banded Liesegang-type structures within a cuprite corrosion crust on an Iranian
bronze fragment (magnification x65o); and D , corroded grain structure of a small
Bronze Age pin, showing remnant grains in a corroded matrix (magnification χ217).

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