Page 218 - Copper and Bronze in Art: Corrosion, Colorants, Getty Museum Conservation, By David Scott

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P L A T E 4 9 Photomicrographs of four samples of chryso­
colla, showing the variable appearance of the mineral
from different sources. Chrysocolla is often fibrous or has
a fine substructure within each particle. These crystals
show a green-blue birefringence when viewed under
crossed polars (all at magnification χ 217).

P L A T E 5 o Photomicrograph of Egyptian blue pigment
used to decorate Ovoid Lekythos, the Canosa vase illus­
trated in F I G U R E 8.2 . The large glassy fragments show
internal detail of darker blue regions. Some pale blue
glassy fragments are also visible (magnification χ 217).
Most samples of Egyptian blue appear blue in color when
viewed under the microscope, unlike some chrysocolla
samples that are so pale they appear only faintly green
or colorless. Malibu, J. Paul Getty Museum (76.AE.95) .

so

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