Ice Elementals
Because the Devs have placed the loot item only in certain places, or from certain kinds of Ice Elementals? Maybe only in places Ice Elementals would be normally found, rather than being spawned by something out of their natural element?
I got mine from the ice elementals in SE Gendarran. There’s maybe a couple dozen there to kill.
https://wiki.guildwars2.com/wiki/The_Grekvelnn_Burrows
was the best place in my opinion.
Fire: Flame Legion heartlands, they’re all over the place, and they’re called Embers
Air: Dwayna’s Temple, hundreds of Sparks.
Earth: Dierdre’s Steps jumping puzzle, right at the start so you do’n’t have to do any jumping
It’s a random drop. I had to kill over 40 ice elementals, 15 in the final location I tried. My friend only had to kill one. So I don’t think we can say with certainty that the ones near the reactor in Metrica don’t count.