Vesper Noble enhancement stones

I have not seen many mobs that drop vesper noble enhancement stones all I see is where they drop in Antharas lair is where they drop so, are there more mobs that drop them like in level 80 plus areas which is the level of the armor only 80-84 can wear it after that it is useless can anyone help me with this I'm on Chronos server buying it for 700k a piece I need a lot I will be there for a few months

Vesper Noble enhancement stones