The crashing waves of the ocean smooths broken glass pieces against the sea floor and makes beautiful sea glass. You do not have to wait for the good fortune of finding nature's sea glass art at the beach. Using a rock tumbler, you can make your own sea glass at home.
Gather pieces of broken glass. Any glass can be used. You can even make your own glass pieces by carefully breaking a bottle. The best way to break a bottle is to wrap it inside a large towel. Put the wrapped glass on the ground outside and tap it with a shovel. Wear thick gloves and dump the glass pieces out of the towel into a bucket. Carefully sweep up any broken glass that falls on the ground.
Put broken glass pieces inside the rock tumbler. If possible, use enough broken glass to fill the rock tumbler almost three-quarters full. Check your rock tumbler instructions to see how much you can safely put inside your particular tumbler.
Fill the rock tumbler with enough water to just cover the broken pieces of glass.
Add 50 g (1/4 cup) sand to your rock tumbler. You can use any type of sand. Sand from the beach works well.
Close the rock tumbler door and turn it on. Let the rock tumbler run for anywhere from 3 hours to 10 days. The longer you let the rock tumbler run, the smoother the glass will be.
Remove the glass pieces (sea glass) from the rock tumbler and rinse them under clear water.
Polish the glass pieces to give them a shiny look. To polish the glass pieces, rub petroleum jelly into the pieces using a toothbrush.