Natural Science in Archaeology

11.2 Building Stone 253
reaches the sea, have been nearly completely rebuilt. The early Qin and Han Dynasty
walls used some stone but also employed soil, clay, sand, wood, and tile.
11.2.2 Porphyry
Many rocks called “porphyry” in the archaeomineralogic literature are granite porphyries.
To geologists, porphyry is a textural term (large crystals in a finer matrix)
that can modify many rock names. The Green Porphyry of Greece and the Red
Porphyry of Egypt have been widely used as ornamental stones since at least the
early days of the Roman Empire. The stone from the Marathonisi Quarries, Laconia,
Greece, the “Marmor Lacedaemonium Viride” of Pliny (N.H. 36.55) was later
known as Porfido Serpentino or Verde Antique/Antico. Mineralogically, this latter
term refers to an andesite porphyry containing crystals of feldspar. In the second
century CE, Pausanias observed that the stone was quarried near the village of
Krokeae, in western Laconia, Greece, and that it was used to decorate swimmingbaths
and fountains (Description of Greece 3.21.4). Porphyry was extensively used
throughout the Roman Empire and can be found in Roman villas in Great Britain
and in Ireland (Ashurst and Dimes 1998).
“The [red porphyry] was first quarried from Lykabettus, north of the hill Gebel
Dukhan in the Eastern Desert of Egypt apparently by the Romans and not by the
Egyptians. This is the only known locality where this rock occurs. Columns nearly
40 ft (12 m) high were sent from Rome for use in St. Sophia, Constantinople”
(Ashurst and Dimes 1998, p. 54). The Romans used porphyry for inlaid panels at
the Pantheon (Werner 1998). The quarries at Gebel Dakhan ceased operation after
the Arab conquest of Egypt in the seventh century CE. After this date, the use of
Egyptian porphyry became very rare, even in Egypt. However, exploitation of the
stockpile of Egyptian porphyry in Rome continued into the medieval era (Deér
1959). Thus, the porphyry found in medieval structures was most likely salvaged
from earlier classical structures.
11.2.3 Basalt/Andesite/Dolerite
Basalt is composed of plagioclase feldspar and ferromagnesian minerals, particularly
augite. It is fine-grained and often extremely tough. Basalt has been widely
used for tools, querns and, in Egypt and Central America, for statues. For a more
detailed explanation of the compositional and textural relationship between basalt,
andesite, and dolerite, see Chap. 3.
The earliest stone vessels in Egypt were Neolithic vases made of basalt. Basalt is
widely distributed in Egypt and was used as early as Old Kingdom times as a paving
material in the necropolis stretching from Giza to Saqqara. The source of the basalt
was the Fayum, where one can still observe the ancient quarry. During Pharaonic