Half-life: 3.05 min
Main emission lines: 583keV, 2614keV
Decay chain: Th-232
Related lines: 238keV, 338keV, 727keV, 911keV, 1588keV
Thallium-208is a short-lived decay product of thorium-232.
It is always present in thorium-232 and is not found separately from thorium.
Thorium is a very common isotope, both in nature and in the home. It is used to make special alloys for electrodes, gas lamp nets, and is found in minerals, building materials (often granite), etc. Unlike radium, it gives off very little radon.