I went to all the stores but found only a small offering of rocks. I drove out to this place in Long Island called www.skyviewstone.com Insane! This was exactly what I wanted, nothing but boulders, rocks pebbles etc. The guy is really cool and you can just walk around the piles of rock inspecting and gathering. Weird suggestion but it worked for me, go on a day when it has rained that week. The water on the floor is useful to clean dirt off the rocks and see what it looks like wet. Have fun!