How to Drill a Shell for Jewelry-Making Close Credit: BRYAN GARDNER Sources Micro Max cordless rotary-tool kit, by Dremel, 8 volt, $89, homedepot.com Diamond-coated twist drill bit (#56), by Eurotool, $6, metalliferous.com What You'll Need Materials Kitchen sponge Shallow plastic container Shell Craft drill Diamond-coated drill bit, 1 millimeter Instructions Place sponge in container. Fill with enough water to just cover sponge. (The water will keep the drill from overheating and the shell from cracking.) Set shell on sponge, top-side down, and hold securely with your fingers, as shown. Keeping edges barely submerged, slowly drill through shell. Explore more: DIY Projects & Crafts