Natural Science in Archaeology

7.10 Zinc (Zn) Minerals 179
and may have been the first zinc mineral to be exploited. Large masses of smithsonite
that are bright green, blue-green, and yellow, as well as nearly colorless, are
frequently found in the upper oxidized zone of zinc deposits. In Europe the classic
deposits are at Lavrion, Greece, and on the island of Sardinia. Zinc ores are found
widespread throughout Germany, Austria, Italy, Belgium, France, and Spain. Two
major European sources of zinc have been the Harz region and the Legenback quarry
at Binnatal, Switzerland. The term zinc may come from the German word zinken,
which means “nails”. Zinc was used to make galvanized nails. The identification of
zinc as an element was by Paracelsus in 1526.
Calamine [the German word is Galmei] is the historic name for zinc ore. In
the eighteenth century it was discovered that what was thought to be one mineral
was actually two: zinc carbonate [Smithsonite] and zinc silicate [hemimorphite].
These two minerals are very similar in appearance. Although still used as a mining
term, calamine is no longer used in mineralogy. Calamine (smithsonite) deposits on
Thasos, Greece, were exploited for lead and silver from the seventh century BCE.
Agricola (1546) reported a white metal that condensed when lead and silver ores
from the Harz Mountains were smelted. He called it “contrefey” because it was
used to imitate gold. He did not recognize it as zinc. The name zinc was not coined
until 1697.
Brass, an alloy of copper and zinc, has been known since classical times. Originally
it was called “yellow copper”. Although perhaps originally formed accidentally
from zinc-containing copper ores, the Greeks learned to add “calamine” (either
hemimorphite [Zn 4 Si 2 O 7 (OH) 2 ·H 2 O] or smithsonite [ZnCO 3 ]) along with their regular
copper ores to produce yellow copper. There are numerous zinc-copper deposits
in the eastern Mediterranean/Near Eastern areas. The Greeks called a “yellow copper
ore” orichalcum from which they made brass. Vergil mentions aurichalcum in the
Aeneid. It seems likely that it was the mineral aurichalcite [(Zn,Cu) 5 (CO 3 ) 2 (OH) 6 ],
which occurs widely as a secondary mineral in oxidized copper-zinc deposits. In
antiquity the zinc content of brass was never more than 28%.
The name sphalerite derives from a Greek word meaning “treacherous”. The
early name for ZnS, blende, also means “deceiving,” apparently derived from the
difficulty of identifying sphalerite in a host of copper ores. The mineral also has
been called zincblende, schalenblende, and blackjack. When rich in iron, it is called
marmatite. Sphalerite is found in a variety of colors: yellow, red, green, brown, and
black, depending on the concentration of other metal cations in the structure. When
it occurs as a transparent variety, it has been used as a gem.
The earliest evidence for the production of metallic zinc is from India and Persia.
Zinc ore is difficult to smelt because zinc volatilizes at about the same temperature
(1000°C) that is needed to smelt the ore. In Europe metallic zinc was not known
until the first zinc smelting process in Bristol in the 1740s. India became known for
the production of “bidri” ware, an inlaid zinc alloy treasured by the Muslim rulers
in Bidar Province in the fourteenth century. The Romans were the first to produce
brass on a major scale. The archaeometallurgy of brass is confused by the use of
the name that is often used to refer to all copper-based alloys (e.g., in the King
James 1611 CE version of the Bible). Brass accounted for approximately one-third