[Agema]

My general experience is that fire gems are relatively less used.

On the battlefield, most fire spells to rain damage down are fairly low fatigue and low-middle level in skill required. The summons are unspectacular, until maybe Conj 8 and the elemental lords. There aren't more magic fire items to make than other paths.

Consequently, I usually assume it's not tough building up a pile of fire gems that can be used for empowerment.