This quest was marked obsolete by Blizzard and cannot be obtained or completed.
If you are interested in helping Sagorne Crestrider in Orgrimmar's Valley of Wisdom, bring him an Azerothian Diamond and a Pristine Black Diamond.
<name>, there is a pressing matter I hope you can help with... both materially and spiritually. Allow me to explain.
Within the depths of the Scholomance in Lordaeron is a chamber called the Great Ossuary. I need to complete a device that would pierce the shadows of this horrid room. To finish what I have started, I need two diamonds: an Azerothian and a Pristine Black. These are not trivial items, I know - I just don't have the resources myself.