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Conservation
The conservation of objects is a technically demanding job, which uses a range of scientific techniques.
Archaeologists who carry out this work need special training and are called 'conservators' (not conservationists!).
When artefacts are discovered, they are often broken, decayed and in a very fragile state. Careless handling can
result in their destruction and the loss of the information about the past which they represent.
Even artefacts that appear to be robust or complete can be subject to less obvious processes of decay; objects do
not always rot on the outside first. Ground conditions greatly affect the sort of materials that survive.
Permanently waterlogged or 'anaerobic' conditions are very good for the preservation of organic matter, such as
wood, seeds and leather. This is because the micro-organisms which cause decay in organic matter need air to
survive. Exposure to air and light can be very destructive and can accelerate the process of decay.
Oxidation ('rusting') of surface deposits can quickly dull and erase colours or traces of ancient writing. Copper
and bronze, which would have been a dark reddish gold when in use, is commonly oxidised to a powdery green colour
when discovered in archaeological deposits. Iron turns a flaky red. Where the oxidised part of the object grows so
deep that there is little of the original left, the object can easily disintegrate.
When discovered, an object may already have been, or may still need to be, removed from the ground conditions in
which it has lain since it was deposited many centuries ago. Lifting an artefact can destabilise it and cause
cracking, so fragile objects are often lifted in a block of soil to help to support them. Contamination by human
touch or the wrong chemicals can spoil the potential for further scientific analysis. Conservators are trained to
know the dangers to ancient artefacts, and how to avoid any unnecessary damage. On-site conservation involves the
careful intact removal of the object; off-site conservation involves the analysis and preservation of the object so
that its full potential to inform us about the past can be realised, and so it may be kept permanently in a museum.
A range of techniques are used to conserve objects: in the case of organics such as wood, the water moisture within
the internal cellular structure which prevented the wood from drying up and collapsing is slowly replaced by
stabilising synthetic chemicals.
Return to Artefacts.
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