Hi Margaret, thanks for your review of the small diamond drill bits and your kind words, much appreciated! Take a look at our article on
how to drill holes in pebbles for some help to stop the drill bits from skittering across the surface and how to get the best out of the drill bits. You might like to try using the
small diamond core drills for your pebbles and glass (I presume it's sea glass). Both types of drill bits work well on all three of the materials you are drilling but for beginners we recommend the core drills. And lastly, here's a link on
how to drill sea glass for you.