I bought some from an ebay seller and most were included , mishapened , i got one good stone out of about 10 . It does cut oddly since You are cutting a thin glass covering and also the corundum. They look like they were drenched in liquid hot glass. i did get a decent polish on the one i cut , i dont want to do anymore. Ill send you some if you want to try them. Just send me a message.