Page 154 - Copper and Bronze in Art: Corrosion, Colorants, Getty Museum Conservation, By David Scott

(1115-1234) of the Song dynasty, but no X-ray diffraction analysis was carried out on these
samples, so it cannot be concluded that they are even basic chlorides.
Atacamite has been found in a variety of Russian paintings from the eleventh to the
fifteenth century and in Russian Romanesque frescoes of thirteenth century (Naumova and
Pisareva 1994). Frescoes from Rostov, Russia, contained atacamite, although it had resulted from
chemical alteration of artificial azurite. Naumova and Pisareva also reported finding atacam­
ite in a fifteenth- to sixteenth-century Russian icon tempera painting. There are no known
occurrences of this mineral in oil paintings. Naumova, Pisareva, and Nechiporenko (1990)
found atacamite in a thirteenth-century manuscript, on a sixteenth-century icon, and in some
seventeenth-century maps. In other studies, atacamite has been found in the wall paintings of
Kariye Camii, a Byzantine church in Istanbul (Gettens 1963 a), and in some thirteenth-century
Austrian churches (Kerber, Koller, and Mairinger 1972). Both atacamite and paratacamite have
been found in polychrome sculpture, Egyptian sarcophagi, and Indian paintings (van T'Hul-
Ehrenreich and Hallebeek 1972). Basic copper chlorides from painted Egyptian objects in the
collections of the British Museum have also been reported by Green (1995). Atacamite was iden­
tified mixed with verdigris in the green paint of a Latin breviary of the thirteenth century, while
the chloride had decomposed in a medieval Greek manuscript, staining the parchment green.
Fitzhugh (i988) reported the occurrence of basic copper chlorides on one seventeenth-
century Indian painting and in several fourteenth- to seventeenth-century paintings from Iran
in the Vever Collection, Freer Gallery of Art, Washington, D.C. No single green pigment is
widely used in the paintings from this collection; some greens are made with malachite or with
a mixture of orpiment and indigo (in Iran) or with indigo and Indian yellow (in India).
A basic copper chloride, either paratacamite or atacamite, was identified by Fitzhugh (1979)
during a detailed study of the pigments used by the Utagowa School of Ukiyo-e, a Japanese
school of painters that operated from the late sixteenth to the mid-nineteenth century. The
paintings studied by Fitzhugh are in the collections of the Freer Gallery of Art. A mounted pig­
ment sample from one of these is shown in PLATE 28. The Ukiyo-e painters do not appear to
have used any verdigris, although they may have used other copper-based green pigments that
have yet to be fully characterized.

Synthetic pigments Theophilus, writing in the twelfth century, describes manu­
facturing viride salsum (probably principally atacamite) by
sprinkling common salt over copper plates brushed with honey and then placing the plates over
vinegar in a closed container (Theophilus i96i). Kühn (1970) reproduced this preparation and
made a mixture of copper trihydroxychlorides and copper acetates. Naumova and Pisareva
(1994), who also attempted to reproduce this recipe, found that after two months only blue crys­
tals of a copper acetate (verdigris) had formed; after another two months a light green deposit

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