Aetherstone
The Aetherstone was a giant crystal orb created by the Nepharim in their pursuit of recreating the world into one that suited them better. It was intended to draw in virtually all the magical energy of the world into one concentrated focal point. With that power, the Nepharim believed they could effect the change they were seeking.
The Aetherstone was shattered after a host of warriors of the civilized races marched against the Nepharim and defeated them after an epic, years-long war.
The shards of the Aetherstone can be used as reservoirs for magical power. They are scattered across the world now but are highly sought-after by wielders of the arcane.