The fingerprinting was
initially aimed at helping to identify unrefined gold stolen from South African
mines. AARL has compiled a Gold Bullion Databank that contains unique source
profiles from ninety per cent of the South African mines, together with profiles
from other gold producing countries.
The profiles reveal minor and trace element impurities, which vary from mine
to mine and even from shaft to shaft. Initially
a microscopic sample of gold is removed by
laser and analysed with a mass spectrometer to reveal the presence or absence
of 58 elements and their 131 isotopes. The resulting profile is then compared
with those in the Databank.
In a test case in
1995, a consignment of 129 kilograms
(4,148 ounces) of gold, claimed to be of Mozambique origin, was proved to have
originated in eleven different South African mines. While the Databank is being
extended to cover mines in many countries, the fingerprinting technique also
offers opportunities for tracking the origin of gold in historic coins
and artefacts, thus providing greater understanding of ancient trade flows,
especially of gold from Africa to Europe.
Anglo American Research
Laboratories (Pty) Ltd.,
Gold Fingerprinting
Technology has been developed
by the Anglo American Research Laboratories (AARL) in South Africa to ‘fingerprint’
samples of gold as an effective means of determining their provenance.
8 Schonland Street
Theta
Johannesburg
P O Box 106
Crown Mines 2025
South Africa
Tel. +27 11 377 4600
Fax +27 11 835 1403