Primordial Echo Trophy trophy_void_rift

What it is for

Loot: exists to be sold or used in a recipe.

Sells to an NPC for about 3,301,471 gold. Weighs 20 of your carry capacity — and weight is what stops drops once the bag fills up.

The best source is Primordial Echo, at 8.0% per kill. You can farm it at Void Rift.