Natural Science in Archaeology

96 5 Gemstones, Seal Stones, and Ceremonial Stones
Citrine. Citrine’s color varies from pale yellow, yellow, to yellow-brown or
reddish-brown. Schmetzer (1988) has shown that color centers in citrine can be
bleached with heating. It is transparent to translucent. The name originates from the
French citron (lemon). It is often erroneously called “topaz.” It was used as gems
and seal stones. Citrine is much rarer in nature than amethyst. Amethyst but not
citrine is noted in the Bible [as one of the gemstones used in decorating the high
priest’s breastplate].
In ancient times citrine was carried as a protection against snake venom. It was
sometimes called “sunstone” because, as a result of its color, it was though capable
of holding sunlight. Natural citrines are rare so today citrines are often heat treated
amethyst or smoky quartz. Citrine can change color permanently if left in direct
sunlight. It was first used in jewelry in Greece in the Hellenistic Period, from the 4th
through the first century BCE. The first use by the Romans was in intaglios (a gem
carved in negative relief) and cabochons in the first centuries CE.
Smoky Quartz. Smoky quartz varies from pale smoky-brown to almost black
and from transparent to nearly opaque. It is also called cairngorm (after a locality
in Scotland) or morion from Latin mormorion. This may be the mineral Pliny calls
chrysolithus, which by his account came from India (N.H. 37.90, 91, 101, 126,
127). Another possibility is that smoky quartz is the mineral Pliny calls capnias.
He does not list its source (N.H. 37.118, 128). It was used as a gemstone and seal
stone. Smoky quartz crystals were used to decorate the breastplate of the high priest
in Old Testament times.
Rose Quartz. This gemstone’s name refers to its color, which varies from pale
pink to deep rose red, occasionally with a purplish tinge. It sometimes exhibits
distinct asterism. Maschmeyer and Lehmann (1983) have identified color centers in
rose quartz. This could be the mineral Pliny calls anteros (N.H. 37.123). It was used
as a gemstone and seal stone.
Tiger-Eye/Cat’s Eye. This mineral can be found in many colors from yellow,
yellow-brown, brown, reddish-brown, through bluish, grayish-green, or green, and
it was used for both gems and seal stones.
Aventurine normally contains small inclusions. This material has also been
called sandastros. According to Pliny, sandastros came from India and southern
Arabia (N.H. 37.100–102). He also mentions a variety called sandrisites but does
not list its source (N.H. 37.10). It was used for gems and seal stones.
5.2.2 Cryptocrystalline Varieties
Chalcedony can be white, grayish, blue, brown, or black. It has a waxy luster and
is transparent to translucent. The name is derived from Chalcedon, an ancient city
of Bithynia in Asia Minor. Ancient sources of this mineral were located in what
is now India, Yemen, and Iraq. It also occurs in Egypt’s Eastern Desert, Western
Desert, Sinai, and other locations. It was used there as early as Predynastic times
(Lucas 1989:392). Pliny’s capnias may be chalcedony. He does not list its source