Shimmerstones
Red or orange glowing crystals, these are used as a lighting source all over the continent, They are mined and polished and carefully cut to keep their inner glow and can be found in almost every household. Unfortunately, the lighting is dim and depending on the quality of the stone unsteady.
Are these stones related to the gems from the gem ferret?
Not at all - they're simply the primary means of lighting besides torches/lanterns in Aran'sha. But interesting thought nonetheless.