Polished sheet brown marble mosaic tiles 9x9=81 tiles Each tile is 15x15x8mm Chop up with hammer and hardie, or if you have an old pair of wheeled nippers you can use them. I've cut up a heap of them and done no real damage. Don't use good ones- just a pair of cheapies to be sure. Maybe even sidebiters would do the trick. $4.50