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. From the journal, you know...* The ruby has been stashed in a barricaded Shadowforge area.* The topaz has been hidden in an urn in one of the Trogg areas, near some Alliance dwarves.* The sapphire has been claimed by Grimlok, the trogg leader.