Crystallized Xanthenite

Older time travel devices that run off nuclear power are so outdated.  All the newer time travel gadgets use this nifty little pink crystal to power their temporal matrices.  Mined in asteroid pockets, pure xanthenite is diluted in liquid ammonia and allowed to crystallize on steel rods.  The resulting xanthenite crystals are shelf stable and usable up to 50+ billion millennia.  Hard to obtain in some dimensions and timelines, these unique gems do the job for any time flow need.