infrared absorption spectrometry

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A technique of physical analysis used to determine the mineralogy or chemical composition of artefacts and organic materials such as amber. A sample is bombarded by infrared radiation, causing the atoms in the sample to vibrate at frequencies characteristic of the material present. That part of the radiation spectrum vibrating at the same frequency as an interatomic bond in the sample is absorbed, while the rest is transmitted. Thus measurement of the extent of absorption at each wavelength in the range 2.5–16 μm provides information on the interatomic bonds associated with the specimen and this can be used to identify the mineral phases and chemical compounds, both organic and inorganic, that are present.

Subjects: Archaeology.

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