Thermoluminescence dating range casuallydating net
Using this information often reduces the uncertainty to 15-25 per cent. Nearly any mineral material which has been heated above 500C at a time one wishes to know is a candidate for TL dating. Porcelains, being nearly vitrified, are a special case requiring a fairly large solid core sample, and TL dating of intact objects is not recommended because of the damage caused by sampling.
Most porcelain dating is done for insurance purposes on broken objects.
Some clays are hardly thermoluminescent at all; some may not have a straight-line relationship between dose and TL; spurious luminescence due to chemical or pressure effects may mask the radiation-induced TL; occasionally, a condition called "anomalous fading", where part of the TL is unstable, may lessen the accuracy of the dose measurement.
Generally speaking, when a sample is drilled and there is no information available about the burial environment, one may expect up to 40 per cent uncertainty.
Much stoneware is not so hard as porcelain and may be sampled by drilling.
The clay cores from lost wax metal castings may readily be tested.
In some categories of objects, from China, for example, the actual age is quite precisely known for short-lived styles, and it is possible to work "backwards" to get information about the environment in many parts of the world, and some other parameters not usually measurable for art objects.
It is an absolute dating method, and does not depend on comparison with similar objects (as does obsidian hydration dating, for example).
The thermoluminescence technique is the only physical means of determining the absolute age of pottery presently available.
Some of these are quite easy to detect; some quite difficult.
For example figures, normally modeled, may be carved out of brick or assembled out of fragments.