Contaminación y conservación de piezas de orfebrería prehistórica. ¿Es el oro un metal sin tiempo?

Abstract

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