Thermoluminescent dating history
The energy released by stimulating the crystals is expressed in light (luminescence).
The intensity of blue, green or infrared light that is created when an object is stimulated is proportional to the number of electrons stored in the mineral's structure and, in turn, those light units are converted to dose units.
Luminescence dating (including thermoluminescence and optically stimulated luminescence) is a type of dating methodology that measures the amount of light emitted from energy stored in certain rock types and derived soils to obtain an absolute date for a specific event that occurred in the past.
Thermoluminescence was first clearly described in a paper presented to the Royal Society (of Britain) in 1663, by Robert Boyle, who described the effect in a diamond which had been warmed to body temperature.
The possibility of making use of TL stored in a mineral or pottery sample was first proposed by chemist Farrington Daniels in the 1950s. The potential of using thermoluminescence to date buried soils developed on colluvial and fluvial sediments from Utah and Colorado, U.
This energy is lodged in the imperfect lattices of the mineral's crystals.
Heating these crystals (such as when a pottery vessel is fired or when rocks are heated) empties the stored energy, after which time the mineral begins absorbing energy again.