Dating techniques for pottery
Minerals, in fact, everything in our planet, are exposed to cosmic radiation: luminescence dating takes advantage of the fact that certain minerals both collect and release energy from that radiation under specific conditions.
Crystalline rock types and soils collect energy from the radioactive decay of cosmic uranium, thorium, and potassium-40.
TL dating is a matter of comparing the energy stored in a crystal to what "ought" to be there, thereby coming up with a date-of-last-heated.
In the same way, more or less, OSL (optically stimulated luminescence) dating measures the last time an object was exposed to sunlight.
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.
The method is a direct dating technique, meaning that the amount of energy emitted is a direct result of the event being measured.
Around the same time dendrochronology was being refined as a dating method with a margin of error less than that of radiometric methods which require expensive equipment and potentially have a greater risk of contamination.
Better still, unlike radiocarbon dating, the effect luminescence dating measures increases with time.
As a result, there is no upper date limit set by the sensitivity of the method itself, although other factors may limit the method's feasibility.
More cautionary offerings., in which events involving influences outside our planet might affect the assumptions upon which some of our radiometrics are based.
Since these events are not frequent occurrences we do not, as yet, have enough data to develop reliable calibration charts.
For over a century this was one of the few dating methods available to archaeologists, but unfortunately it could not offer specific dates.