Fossil trilobites are actually not all that uncommon. And usually they are left in the rock they are found in. Since fossilization basically turns them into "rock", it would be difficult to separate the fossil from the surround matrix.
If I remember, what I can do is download your photos and pass them on to one of my rock club's fossil experts. I have his email addy so I can send him the pics and ask him if he knows what it is. He's quite good with fossil ID. He hunts fossils and has all kinds of cleaning equipment.
Actually now that I think about it, I could email Bob Simon. He is another one of our club members who is a commercial dinosaur hunter. He found the 3rd best example of a stegasaurus which was excavated 3-4 years ago and sent to Sweden for final cleaning and assembly. She has just returned to the U.S. and is now in the process of being marketed. Bob just uncovered part another large dinosaur--a 20-foot tail section and he is very excited about what he might find this summer digging this one.
Bob owns/runs Dinosaur Safari out in Shelle, Wyoming. You can make arrangements to go out and dig on his excavation site if hunting for dinosaur bones is something you've always wanted to do. His website is www.dinosaursafaris.com. Bob is a cool guy and people have a blast digging out there and usually find lots of stuff.