You see a soul stone.
It weighs 0.30 oz.
It contains the essence of countless tormented souls.
Notes
It was hard to obtain, because it's only lootable from Necropharus which was only a rare spawn, supported by many Necromancers. But due to a quest and now that it spawns in different places, it has become a little bit easier to obtain.
Needed for an addon of Mage Outfits (male) / Summoner Outfits (female).