Absolutely you can. Quite often you'll find geodes with small crystals, but I agree with what others have said, to find really good crystals you not only need to know where to look, but as with most things on our small island, you need permission to go and look in most of the best seams. You can strike it lucky sometimes around Cornwall, The Pennines and other parts of the Midlands. Be patient and keep your eyes peeled and you never know. Be aware as well that sometimes, what looks like a piece of rock can be transformed by polishing in a tumbler