Recover all three gems and a power source for the necklace from Uldaman, and then bring them to Jarkal Mossmeld in Kargath.  Jarkal believes a power source might be found on the strongest construct present in Uldaman.$B$BFrom the journal, you know...$B* The ruby has been stashed in a barricaded Shadowforge area.$B* The topaz has been hidden in an urn in one of the Trogg areas, near some Alliance dwarves.$B* The sapphire has been claimed by Grimlok, the trogg leader.