Natural Science in Archaeology

166 7 Metals and Related Minerals and Ores
7.6 Iron (Fe)
Iron has the chemical symbol Fe from the Latin ferrum. Iron is the fourth mostcommon
element in the earth’s crust. Because iron combines readily with oxygen,
sulfur, and other anions, it is rarely found in the native state. Native iron does occur
as minute pellets in basaltic rocks in many areas including Ireland, Scotland, France,
Germany, Poland, Russia, Japan, Canada, and the United States. The only significant
occurrence of large masses of native iron in basalts is on Disko Island, Greenland.
Native iron is also found in carbonaceous sedimentary deposits in a few localities.
Both native iron and meteoric iron (see below) are quite rare, so the technique
of smelting iron oxide ores had to be developed before iron became a widely used
metal. For good summaries of the transition from the Bronze Age to the Iron Age,
see Waldbaum (1978) and Wertime and Muhly (1980). Waldbaum’s work was
updated by Muhly et al. (1985). In 1999, Waldbaum reviewed the current status
of our knowledge and provided a map of eastern Mediterranean and Near Eastern
Bronze Age/Early Iron Age sites at which iron had been found.
True iron metallurgy originated in ancient Anatolia in Hittite and Mitanni kingdoms
over 3000 years BP and separately in India at about the same time. Iron came
to be used regularly in Europe by the middle of the first millennium BCE. Agricola
in his ‘De Re Metallica’ describes the mining of metal ores in Europe. Much earlier
in Saxony, two types of low-grade bog iron ore provided the raw material for Early
Iron Age (and onward) iron production. The two types were distinguished by their
manganese and barium contents. Slag compositions showed that both types of ores
were inefficiently processed (Heimann et al. 1998).
Along with the question of iron usage in the Bronze Age of the eastern Mediterranean,
we have the question of early steel. Smith et al. (1984) report on a Middle
Bronze Age steel blade from Pella, Jordan. The metal contained 0.9% carbon that
was distributed heterogeneously, calling into question whether the carbon was purposefully
or accidentally incorporated. This blade marks the earliest known steel
from the eastern Mediterranean region. The report by Williams and Maxwell-Hyslop
(1976) on “Ancient steel from Egypt” is inconclusive because the carbon content is
in the range 0.1–0.2%. However, even this low amount of carbon resulted in moderate,
but workable, increases in hardness.
Perhaps the most famous early steel was “Damascus steel” used in Near and
Middle Eastern sword-making circa 1100–1700 CE. These swords were noted for
both sharpness and strength. The basis for Damascus steel is “Wootz steel” which
originated in India about 500 CE and spread to Persia. The finished steel had a visible
grain pattern, the result of alignment of Fe 3 C particles in the steel. Damascus
steel was not produced in Damascus, but rather in India, and ingots were shipped to
Syria where the weapons were forged.
References to what iron ore deposits were exploited are scarce in the literature.
Iron oxide minerals are almost ubiquitous at the earth’s surface, so early iron metalsmiths
did not have the resource problem faced by bronzesmiths. As stated earlier,
iron makes up about 5% of the earth’s crust, whereas copper is only 0.005% and tin
is a scant 0.0005%.