Calypso13: This one can be more than a little difficult to find, yes. It gave me fits, for almost a half-hour, when I was trying to find it.
What you are looking for is a very small pile of dirt, against a wall in the Dig Site; it's so small, that it is very, very easy to walk right past it ... several times, even. I would recommend slowly and carefully searching along the walls of the Dig Site.
As I recall, I found it near the NPC in there (I forget his name), but it wouldn't surprise me if it's location was somewhat random.
It's quite easy Watson! As you first go into the excavation site in the Royal Hall, you look at the wall right before you go to the Professor. Please note, that if someone recently dug in the dirt pile, you may not see it. Two things you can do is 1. Wait a few moments for it to reappear or 2. Change Realms(servers). Good Luck on all of your quests.