Hallows, if you don't have Pristine Black Diamond, you can farm it in Dire Maul, Stratholme, Scholomance , drops from random mobs.
I need 10, paying 3k each, that's 30k gold for 10. If you have any, please COD to Thewiszard on Ragnaros (Alliance).

PS: please do not mistake this item for the prismatic black diamond from JWC.

Thank you for your time.