- Chapter Sixteen -
and the recycling of gold already in circulation either within the Celtic world or
from outside it, often in the form of Greek or Macedonian gold coins. Gold naturally
contains a variable amount of silver, ranging from a fraction of I per cent to 30 per
cent or more, the higher silver natural alloys often being referred to as electrum
(Lehrberge forthcoming). During the later Bronze Age it had become standard
throughout most of Europe to alloy gold with up to 10 per cent copper, perhaps to
improve the mechanical properties, perhaps to counteract the whitening effect of the
silver naturally occurring in the gold.
As we will see, from the eighth century Be onwards there was a change in the use
of gold across much of Europe with a gradually increasing tendency to deposit it
with burials. The large late bronze age hoards disappear and the gold alloys used in
them were no longer available. The gold used in the Hallstatt period is unalloyed and,
depending on area, could be either vein gold or placer gold (e.g. Hartmann 1987;
Hofmann 1991). From the beginning of the La Tene period the copper content
begins to rise again but seldom exceeds 5 per cent (e.g. Eluere 1987a; Voute 1991)
until the first century Be when both coinage alloys and many of the alloys used
at Snettisham must be described as ternary alloys with up to 40 per cent or more
copper (Stone 1987; Northover 1992). Similar ternary alloys appear in the rather
separate development of gold alloys in Iberia (Pingel forthcoming).
Around the middle of the first millennium Be the process of parting gold-silver
alloys with salt to remove the silver was discovered, probably in Mesopotamia.
Combined with the process of cupellation to remove base metals, this meant that
gold could now be refined to better than 99.5 per cent purity (Eluere 1989a). As far
as we know at present these techniques were not known to Celtic goldsmiths
but high-purity gold could enter the system via the Macedonian gold coinage and
some natural high purity sources (Eluere 1987b). Little thought has been given so far
to the origins of silver used in the Celtic world and we await the application of lead
isotope analysis more extensively. The final precious metal known to the Celts was
mercury, attested by several mercury-gilded torques and other objects at Snettisham.
HALLSTATT
Metallurgical issues surrounding the end of the conventionally defined Bronze Age
and the adoption of iron as a utilitarian metal in what became Celtic Europe are
complex and often misconstrued. The period is also one of considerable social change.
There are stark contrasts between the increasing wealth and power of the chiefdoms
in the core area of the Hallstatt culture, evidenced by the princely graves, and
the periphery, where regions such as the British Isles saw a rapid decline in the avail-
ability of finished metal despite apparently adequate resources of copper, tin, iron and
even gold. The production of gold, and the uses to which it was put have to be seen
against this background. One of the principal effects was that the accumulation of large
numbers of near-identical objects in hoards, as in late bronze age Ireland, ceased and
gold begins to be deposited in high-status graves. In other words gold has ceased to
be a measure of wealth with, perhaps, a primitive value system attached to it, and
has become a symbol of power. No one has ever made any calculations but a casual