Page 116 - Copper and Bronze in Art: Corrosion, Colorants, Getty Museum Conservation, By David Scott

Notes
ι Pliny the Elder Natural History 34.1 (Pliny 1979).
2 Copper gives smooth parabolic oxidation curves
at 00 °C and discontinuous breakaway curves
8
at 500 °C, where the oxide growth is brittle.
These curves are derived from plots of the weight
increase (in milligrams) against time (in minutes).
3 Chlorine ions, along with O , are the most com­
2 -
mon corrosive agents contiguous with the metal.
4 Plutarch Moralia, the Oracles at Delphi no longer
given in verse 5.35ic-5.438 e (Plutarch 1984).
5 Pliny 34.24.
6 Pliny 34.22.
7 Research by the author.
8 The copper in turquoise-blue glasses, and in the
glazes often used on Egyptian faience, occurs
in the cupric state rather than as cuprite.
9 John Twilley, letter to the author, 14 September
1998.
10 This is the first account the author has been able
to find on the use of tenorite as a pigment. Its use
was probably always restricted because of mala­
chite's importance as a copper ore.
11 The presence of the calcium silicates needs to be
confirmed, and the calcium oxide may actually
have been calcium hydroxide, Ca(OH) 2.
12 Greek name for Amenhotep II, pharoah of Egypt
from ca. 1426 to 1400 B . C . E .
13 Kinetic rather than thermodynamic control
appears to be dominant in this reaction since, if
the solution is not stirred, the initial precipitate
settles out and chalconatronite and georgeite
form. Recrystallization of both dimorphs of
CuC0 3Cu(OH) 2 occurs if they are left in con­
tact with the blue solution of bis (carbonato) cu-
prate(II) ion, [Cu(C0 3) 2] "(aq).
2

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