31
Middle East in the ninth century or before and subsequently spread
through Egypt, Spain, and other countries. A particularly fine period
of development occurred in Spain with Hispano-Moresque ware, a
glazed ceramic made by Moorish potters largely at Málaga in the
15
th century and later at Manises near Valencia in the 16
th century.
To produce this type of lusterware, a glaze was first applied over a
design and the piece fired to produce a thin, hard coating. Glazes
were based on dry powdered minerals or oxides, which commonly
included tin and copper. After the first firing, the luster coating,
consisting of metallic pigments (normally copper or silver compounds) mixed with clays, was brushed on over the glaze. Then the
piece was fired again but at a lower temperature and within a reducing atmosphere (a condition whereby a reducing agent chemically
causes a change in a material with metallic compounds to a metallic state by removing nonmetallic constituents as it is itself oxidized
by donating free electrons). Afterward the piece was cleaned and
polished to reveal the resulting metallic sheen.
Later examples include the “tin-glazed” pottery of 15
th and 16
th
century Italy and the “copper glazed” lusterware porcelains of
Wedgwood in early 19
th century England. Several studies of medieval lusterware via transmission electron microscopy (TEM) have
been undertaken to understand the composition and microstructure of luster. Results have clearly indicated that various luster
characteristics can be described in terms of the presence of different levels of silver or copper nanoparticles within the glassy
matrix. The associated surface plasmon effects (described previously) cause the appealing metallic sheen to develop. Again,
though the artisans producing lusterware lacked an understanding of the chemical processes that achieved the optical effects and
were unaware that their empirical processes led to the creation
of nanoparticles, the craft-based development of the requisite
knowledge was remarkable.
Similarly intriguing was the development of the beautiful blue
paint found in the murals and pottery of the ancient Mayan world
(see Figures 2.19 and 2.20). The Mayan blue has long been admired
for its marvelous color qualities as well as its inherent resistance to
deterioration and wear over long periods of time. Various natural
alkalis, oxidants, mineral acids, and other agents seem to have little
effect on the blue paint of the Maya. Unlike the blues of Europe
and Asia, largely based on ground lapis lazuli, the origin of the
Mayan blue was likely a dye known as anil, which is found in preColumbian textiles and is obtained from a local plant to produce
indigo. Normal indigo, however, is not acid resistant and its use
Nanomaterials in Art and Cultural Heritage
Figure 2.17 The Lycurgus cup looks green
when light shines on it but red when a light shines
inside it. The cup contains gold nanoparticles.
(Courtesy of the British Museum.)
Middle East in the ninth century or before and subsequently spread
through Egypt, Spain, and other countries. A particularly fine period
of development occurred in Spain with Hispano-Moresque ware, a
glazed ceramic made by Moorish potters largely at Málaga in the
15
th century and later at Manises near Valencia in the 16
th century.
To produce this type of lusterware, a glaze was first applied over a
design and the piece fired to produce a thin, hard coating. Glazes
were based on dry powdered minerals or oxides, which commonly
included tin and copper. After the first firing, the luster coating,
consisting of metallic pigments (normally copper or silver compounds) mixed with clays, was brushed on over the glaze. Then the
piece was fired again but at a lower temperature and within a reducing atmosphere (a condition whereby a reducing agent chemically
causes a change in a material with metallic compounds to a metallic state by removing nonmetallic constituents as it is itself oxidized
by donating free electrons). Afterward the piece was cleaned and
polished to reveal the resulting metallic sheen.
Later examples include the “tin-glazed” pottery of 15
th and 16
th
century Italy and the “copper glazed” lusterware porcelains of
Wedgwood in early 19
th century England. Several studies of medieval lusterware via transmission electron microscopy (TEM) have
been undertaken to understand the composition and microstructure of luster. Results have clearly indicated that various luster
characteristics can be described in terms of the presence of different levels of silver or copper nanoparticles within the glassy
matrix. The associated surface plasmon effects (described previously) cause the appealing metallic sheen to develop. Again,
though the artisans producing lusterware lacked an understanding of the chemical processes that achieved the optical effects and
were unaware that their empirical processes led to the creation
of nanoparticles, the craft-based development of the requisite
knowledge was remarkable.
Similarly intriguing was the development of the beautiful blue
paint found in the murals and pottery of the ancient Mayan world
(see Figures 2.19 and 2.20). The Mayan blue has long been admired
for its marvelous color qualities as well as its inherent resistance to
deterioration and wear over long periods of time. Various natural
alkalis, oxidants, mineral acids, and other agents seem to have little
effect on the blue paint of the Maya. Unlike the blues of Europe
and Asia, largely based on ground lapis lazuli, the origin of the
Mayan blue was likely a dye known as anil, which is found in preColumbian textiles and is obtained from a local plant to produce
indigo. Normal indigo, however, is not acid resistant and its use
Nanomaterials in Art and Cultural Heritage
Figure 2.17 The Lycurgus cup looks green
when light shines on it but red when a light shines
inside it. The cup contains gold nanoparticles.
(Courtesy of the British Museum.)