How to Create Sea Glass

Get a rock tumbler, such as the Model T Kit Rock Tumbler and the SciEd Rock Tumbler. A large one is unnecessary unless you plan on tumbling a lot of glass. It could pay off if you do, since you can't load tumblers all the way (that would cause damage) and they have to run for days at a time depending on how smooth you want the glass to be.

Choose your glass. If you already have shards of glass, use that. If not, you can easily crush glass plates, bottles or panes by placing them inside a thick bag, such as a padded backpack, and stepping on it repeatedly. For more precision, use a tile nipper. This can cut glass into different shapes. The shapes can't be too intricate, but something simple such as a circle, triangle or heart would work.

Fill the broken glass into the tumbler. Don't full it all the way to the top as that could break it, or shorten its lifespan. Fill it full of glass two third's of the way. Next, fill the tumbler with enough water to cover the glass. Then add about a half a cup of sand.

Depending on how smooth you want it, leave the tumbler running for a few days in a closed off area such as a garage or basement where the noise won't disturb anyone. If you want it to be rough, a few hours will be good enough. Check the glass at least every two days and rinse the glass, adding new sand and water each time you open the tumbler.

When the glass is smoothed to your satisfaction, clean the glass off, and use it as you wish.