added by archaeologs Technique Principle. A sample is volatilized or vapourized by a spark discharge or laser beam. This also excites electrons within the sample, causing light to be emitted. The wavelengths of this light are related to the chemical composition of the sample. Thus, if the spectrum of light is analysed, it is possible to calculate the concentration of different elements. Materials. Metals, glasses (natural and manmade), pottery. Between 5 and 100 mg of material are needed. Applications. Optical emission spectrometry has been used with great success to establish the sources of obsidian artefacts in the Near East and Mediterranean. This is done by matching the concentrations of trace elements found in artefacts with those of the obsidian sources. Similar work has been carried out on pottery, although the larger number of possible origins for this material makes sources difficult to establish. The technique has also been used to investigate minor and trace elements in bronze and copper artefacts.
The Macmillan dictionary of archaeology, Ruth D. Whitehouse, 1983