For warriors, this meant not only durable armor but weapons
that were less likely to break under stress.
GREECE
BY JOHN W. HUMPHREY
As early as the second half of the Neolithic Age (ca. 5000–ca.
3000 b.c.e.), people began to work soft native metals such as
copper and gold, which they could form into shapes by ham-
mering with traditional stone tools; hence this period is called
the Chalcolithic, or Copper Age. But the shapes of these items
were so limited and the malleability of the native metals so
high that they could not be used as functioning tools or weap-
ons. Th e discovery of primitive casting techniques produced
more functional shapes, but the off -gassing of molten copper
restricted the casting to open, one-piece molds of sandstone
or clay, so this technique left one fl at surface on the tool and
used much precious metal.
By the Bronze Age (ca. 2800–700 b.c.e.) kilns designed
originally for fi ring ceramics produced temperatures high
enough (about 2000 degrees Fahrenheit) to smelt copper
from its carbonate and oxide ores. It seems likely that copper-
based pigments used to decorate ceramics were accidentally
smelted in pottery kilns, leaving behind beads of pure copper.
Th is copper was then combined with arsenic or tin to pro-
duce bronze, a metal superior to copper because of its lower
melting point, ease of casting, and hardness. Th e invention of
two-piece molds then allowed symmetrical tools to be cast,
and it saved metal because a removable core could be inserted
into the mold to create a hollow object. Such metal tools had
several advantages over those of stone: Th ey were thinner,
sharper, and more durable; they allowed a greater variety of
forms; and they could be reworked when dull or broken.
Th e processing of ore to extract the desired metal gener-
ally followed a common procedure, though some stages were
omitted for certain metals. What follows is applicable to ores
of copper, tin, and lead/silver, but not gold (which was always
available naturally in its pure form) or iron.
Because most ores contain sulfur or oxygen, the fi rst
requirement is to separate these from the desired metal.
Th is was done in a simple roasting oven, in which the ore
was layered with the fuel (usually charcoal), covered with
a temporary shell, and burned in a reducing atmosphere;
the carbon combined with the sulfur or oxygen and gassed
off , leaving the desired metal behind, though still combined
with impurities.
Th e ore was then broken up by crushing it either in mor-
tars with an iron pestle or in mills that resembled the large
“hourglass” grain mills familiar from Pompeii and Ostia. Th e
crumbles were then either sieved or, more commonly, washed
to remove the unwanted gangue (surrounding rock), which,
because it was heavier than the metal, was left behind on the
washing table. Th is process is well known from the surviving
washing tables at Laurion, Greece, which ingeniously used
recirculated water.
Th e remaining concentrated ore was then heated in a
smelting furnace with suffi cient temperature to produce a
molten metal that separated from the unwanted slag; the two
would generally be tapped off at diff erent heights accord-
ing to their specifi c gravities. Th ree elements were required
for this procedure: a furnace, suitable fuel, and a supply of
forced air. Open hearths were fi rst used as furnaces, but
they proved unsatisfactory because they could not sustain
the necessary temperatures. However, in classical shaft fur-
naces, like those used for fi ring pottery, the charcoal and ore
could be properly layered and the heat concentrated within
the restricted space.
Th e preferred fuel was charcoal, the only material that
could generate suffi cient and continuous heat for smelting.
Other fuels were tried—wood (before the deforestation of the
Mediterranean), lignite coal, and even dried dung—but with
little success. Th e Greeks (like their Egyptian predecessors in
the Bronze Age) used bellows to provide a constant supply of
forced air to maintain the necessary temperature for smelting
copper, though pipettes were used for smaller quantities of
precious metals. Th ese bellows were generally fabricated from
the skins of animals, with fl aps of skin serving as inlet and
outlet valves and terra-cotta nozzles to protect them from the
heat of the fi re. Th ese bellows were oft en used in pairs and
operated by foot to produce a constant fl ow of air.
Once the metal had been tapped off , it was usually al-
lowed to cool and solidify into ingots before being remelted
and cast. Only occasionally did the casting of a fi nal product
seem to have been done directly from the smelting stage. Be-
fore being worked into its desired form, silver was subject to
further refi ning by cupellation: Th e smelted ore was placed
in a porous clay crucible and heated; the residual lead wasGold mask from Mycenae (Alison Frantz Photographic Collection,
American School of Classical Studies at Athens)684 metallurgy: Greece