Cool, I'd like to see some clearer pictures of it, might want to make one for my community tank. Guess you could use shards of slate, if you sanded down the edges with a Dremel so they wouldn't be sharp? Just don't think the gravel would go good with the sand in the tank. Did you use silicone or epoxy to stick the stuff on it with? Sorry 'bout all the questions, looks like a fun project that I'd like to try.