Come on, people, it’s not like you can just sit them down any old place. Their placement must be precise and specific to whatever issue you’re trying to address. It's easy to place crystals places where they hurt the sound. People sometimes ask me, "Hey, how come you charge so much for Brilliant Pebbles? They look like you got them out of an aquarium." I use a number of pure crystals, both semi precious and precious stones, of various types. Some of the crystals I use are sapphire from India, ruby from Burma, topaz, tourmaline and even diamond.