Contamination and preservation of prehistoric craftsmanship pieces. Is gold a timeless metal?

Abstract

The properties of gold have led to its being considered completely resistant to attack and tothe passing of time. This is, in fact, only partially true, since as a result of certain of thecharacteristics of gold (or of metals alloyed with it), and of the environment surroundinggold pieces, the material may be attacked by various contaminants of different origin. Thismay be important in the case of "archeological gold", which is subject of study by theDptment. of Prehistory, Institute of History, in collaboration with the Dptment. of PhysicalMetallurgy of CENIM. This paper provides a general view of the properties of gold, the wayit is obtained, etc., and includes two examples of pieces from the Historic Trust, as samplesof a metal that is, on the one hand eternal and immutable and, on the other, a changingelement that ages, deteriorates and becomes contaminated. The first example consists oflaminar fragments from the dolmen at Matarrubilla (Seville), dated from the 3 millenniumB.C., while the second consists of fragments from two diadems-belts from Moñes (Asturias),dated between the third and the first century B.C.