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.
However, problems arise from assuming a uniform radiation dose rate over any significant period of time and assuming that the TMRD resulted from the object or artifact being in a strictly constrained environment identical to that in which it was found.
Thermoluminescence Dating Thermoluminescence can be used to date materials containing crystalline minerals to a specific heating event.
This is useful for ceramics, as it determines the date of firing, as well as for lava, or even sediments that were exposed to substantial sunlight.
Both assumptions become less realistic with the passage of time.
Another problem with the TMRD is the calibration of the detector, since different crystals in an artifact can contain different amounts and/or types of luminescence material.