Page 266 - Copper and Bronze in Art: Corrosion, Colorants, Getty Museum Conservation, By David Scott

Egyptian references to the mineral (Lucas 1962) tell of turquoise from Sinai and mention
"new" turquoise. This designation refers to stone that has not decomposed with exposure to
light and heat; the value of such "new/' unsullied turquoise would certainly have been recog-
nized. An example of turquoise that decomposed during burial is found on a chlorite schist ves-
sel from Eastern Iran or Bactria, dating from the early to middle of the third millennium B.C.E.
(Meyers 1996). Although the inlays have become whitish, X-ray diffraction analysis identified
them as being originally turquoise in composition. Documented occurrences of turquoise for
intaglio or cloisonné work are numerous, although it is not always clear how the identification
of the mineral was confirmed. A circular belt ornament from the Western Han dynasty
(206 B.C.E.-24 C.E.), now in the Shumei Family Collection, Japan, is decorated with hundreds
of thin polygonal turquoise disks that are contrasted with red carnelian and a bronze patina. In
the same collection are gold bracelets from the Achaemenid dynasty (525-404 B.C.E.) of ancient
Persia that have winged caprid (goat-shaped) terminals inlaid with cloisonné work in lapis
lazuli, carnelian, turquoise, and a vitreous paste (Shumei Foundation 1996).
I TURQUOISE ARTIFACTS FROM THE NEW WORLD One of
the precious objects presented to the Spanish conquistador Hernán Cortés when he arrived in
Mexico in 1519 was a mask made of turquoise mosaic. In the New World, smaller objects, such
as rings, beads, or pendants, were carved from solid turquoise, while larger objects were often
made of wood covered with turquoise tesserae. Despite an extensive turquoise industry, there is
an almost complete absence of sources for the mineral in ancient Mesoamerica. Turquoise
mines were located in the desert regions of the American Southwest from California to New
Mexico and in Chihuahua, Mexico. Harbottle and Weigard (1992) analyzed numerous turquoise
samples from forty mines in the American Southwest and compared their elemental profiles
with those of two thousand samples from twenty-eight sites in both the Southwest and Meso-
america. The research showed that turquoise from the Southwest traveled not only to central
Mexico but even to the Yucatan Peninsula. During the classic period in Mexico, around 700, the
site of Alta Vista was an important turquoise workshop that used raw material from mines at
Cerrillos in New Mexico. This Cerrillos turquoise has been identified in objects from the Mexi-
can states of Sinaloa, Jalisco, and Nayarit (Lambert 1997).
Turquoise was worked closer to its southwestern sources during the Pueblo I I period,
around 1100, especially at Chaco Canyon in Arizona. By the mid-thirteenth century, numerous
new mines had been located in various areas that supplied turquoise not only to craftspeople in
the Southwest but also to the Aztecs by way of a Pacific coastal trade route as well as an inland
route (Harbottle and Weigard 1992).
Some light-blue beads were examined from the first-century C.E. site of La Miña, not far
from Sipan in the area of Peru occupied by the Moche (Scott 1994b). The X-ray diffraction data
showed that the mineral used to make these small beads, originally thought to be turquoise, was,

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