Select a piece of sea glass to be used, preferably a thinner and flatter piece. Use the 18V ONE+ dual temperature glue gun to stabilize a piece of sea glass to a flat board. Allow time for the glue to dry.
Insert the diamond bit into the 1.4 Amp rotary tool collet. Plug the rotary tool into the 18V ONE+ 150 watt power source and then press power to turn on. Turn the 1.4 Amp rotary tool speed to high.
Slowly bring the diamond tip engraving burr to the stone and start drilling the rock. Pause every 15 seconds to limit the amount of pressure on the rock to ensure the rock doesn't crack.
Switch the accessory to the mandrel with the screw and attach the polishing wheel. Guide the polishing wheel along the rocks.
Cut a small piece of wire to 3 inches. Thread the wire through the drilled hole and tightly loop around the hole twice. Slide the jump ring onto the longer wire piece and twist the two wires to tighten around the jump ring. Cut the excess wire.
Open the necklace chain. Thread the smaller end through the jump ring and then clasp the necklace closed.