Ok, I know it's a dumb question but I got my hands on 2 small pieces of a purple and multi-color chalice. My question is, am I supposed to glue it to an existing rock so it can encrust into it and grow or will it grow on it's own if I just lay it on the sand bed? Never called my attention but at $15 for a silver dollar size, I couldn't resist the temptation the evil fish god set before my eyes....