There is a price to pay for all things in this world. The price for the specific item that you seek is thirty gold pieces.
Naturally, I shall retain the majority of the components which you collected. But worry not, you shall have your trinket.
It is disgrace to his memory... a mortal, such as yourself, finishing his life's work.
Take your amalgamation and be gone!
Black Diamonds drop from various mobs in Blackrock Depths, Lung Juice Cocktail is a reward from turning in 3 Blasted Boar Lungs, 2 Scorpok Pincers, and 1 Basilisk Brain to Bloodmage Drazial in the Blasted Lands, Libram of Constitution is a world drop from level 50 and higher mobs, and Night Dragon's Breath are picked from plants in Felwood.
You will be rewarded with the following: