The Crumbling Past

You can complete this quest pre-cata if you don't stray too far into Uldum. As long as you don't leave the hallway leading into the large room you should be able to kill enough of these guys to finish the quest.

The enterance to the Uldum is 37.75,80.62. Watch out for the giant Guardian that comes out after you turn in the quest at the chest.

Enter the Ruins of Uldum (37.7/78.9) and kill the white mobs (Sandstone Earthen) kneeling along the edges of the entrance path (along the walls). They will drop the Earthen Jewel needed to complete this quest. You will sometimes have the ability to loot the mobs, but get the message that there is no loot. Found this to be quite odd, as if there is no loot, then the loot mouseover shouldn't even appear.