Find the Gems and Power Source

Here is the journal, translated for you to read on your own. The crux of it says dwarves hid the ruby, the troggs hid the topaz, and a trogg named Grimlok has the sapphire. Look - you're going to need a power source to make the necklace work again. Dran Droffers doesn't know this. To find one, here's what I'd do: go as deep as you can in Uldaman and kill whatever construct there is the strongest. No doubt whatever that is would have it. When you have everything collected, come back here!