Archaeological cultural property presents the conservator with special challenges, as the state of preservation is often worse than for pieces stored above ground, and in cooperation with archaeologists it must first be determined from which epoch and culture the pieces originate.
The work of the conservator begins immediately at the moment of recovery of the archaeological find. It must be conserved immediately after the find in order to prevent its further deterioration. Whereas in the past the motto was to restore the originally intended message of the piece - which sometimes meant not only imitating the original state, but even putting the piece in a state that had never existed in the first place - today, in the vast majority of cases, it is simply a matter of conservation. The goal of the work is not to make the piece look like new, but at best to preserve it from further decay. The traces of time are an important part of the piece, and erasing them would mean destroying information.
Archaeological cultural property and its place of discovery
Sometimes the find has already been in an environment conducive to its preservation at the site of discovery, and the process of decay only begins with recovery - for example, in the case of pieces from bogs or bodies of water that have been preserved by the moisture, acidity of the soil, or lack of oxygen. Here, the goal is to slow the decay as much as possible even after recovery, which can be achieved, for example, by storing the object in a similar environment, at low temperature fluctuations, or under exclusion of air.
In other cases, salvage and preservation alone can save the find from certain decay, such as with metal objects that have become saturated with salts in the soil and must be desalinated.
Materials and their preservation from decay
Most archaeological finds consist of relatively stable, inorganic material that does not decompose or decomposes only very slowly in the soil - such as ceramics, objects made of stone, metal or glass. Nevertheless, these are also subject to decay processes that need to be stopped or slowed down. When possible, the shards of ceramic and glass vessels are reassembled - however, given the sheer abundance of finds, this is usually only done on a very small selection of pieces and only for exhibition purposes.
The situation is more complicated with more unstable materials, such as textiles, wood, papyrus or leather. Organic material is susceptible to decomposition by small animals, microorganisms, and mold, so it is important to prevent infestation; in addition, fluctuations in humidity and temperature can lead to swelling or shrinking processes, which can result in stresses in the material, cracks, and holes. Since textile material has sometimes also been dyed with natural dyes, the decay of these colors should also be prevented if possible.
If the objects were found in an environment that was conducive to their preservation - for example, the writings of Qumran, which survived in the extremely dry air of a cave above the Dead Sea for almost two thousand years, or the mummies in the Chinese Takla Makan - then this environment should be maintained if possible. In most cases, however, they have been in relatively moist soil and must be dried slowly and gently.
Because archaeology and restoration are so closely intertwined and the work of a conservator specializing in archaeological pieces requires very specific expertise, branches of training have existed since the mid-20th century and degree programs in archaeological restoration since 1989.