These slowly decay over time and the ionizing radiation they produce is absorbed by mineral grains in the sediments such as quartz and potassium feldspar.
The radiation causes charge to remain within the grains in structurally unstable "electron traps".
Luminescence dating refers to a group of methods of determining how long ago mineral grains were last exposed to sunlight or sufficient heating.
It is useful to geologists and archaeologists who want to know when such an event occurred.
This is the technology used for dosimetry badges in areas where radiation safety is a concern.
Blue thermoluminescence dating using different measuring techniques of the same sample material from one site (the Mála dune) yields somewhat lower ages, varying around 125 ka.