Beachcombers across the world spend their free time searching for broken bits of glass polished smooth by waves and sand. On ocean beaches, collectors call the shiny shards sea glass. On inland shores, enthusiasts refer to the naturally polished fragments as beach glass. In the United States, beachcombers often congregate on the shores of Cape Cod or Lake Erie to discover the colorful gems often used in custom jewelry.
Walk in one direction along the wrack line--the line of debris left by the last high tide or storm. Examine closely places with many tiny stones. Walk the same line in the opposite direction. If you found one piece of glass, search the area again for pieces you might have missed.
Make another pass along the beach at the water's edge. Walk slowly, sweeping your eyes from your feet ahead about a couple yards and from side to side in an arc of a couple yards away from water. Examine pockets of small stones for glass. On rocky beaches, the pieces may be tucked in the lee of larger stones.
Turn and retrace your steps about 10 to 12 feet away from the water, again sweeping your eyes from feet to ahead and side to side. Repeat these passes until you have covered the beach.
Watch for reflective surfaces. Bright sunlight usually helps by reflecting glint or gleams. Don't overlook bright days in winter if the beach isn't frozen.
Comb beaches near where creeks, streams or rivers enter. Many years ago trash dumps were common along these paths where bottles and other debris washed into the lake or ocean. Some of the finest glass gems have been polished by waves and sand for decades. Some of the rarest colors are from glass that hasn't been common for a long time. Red glass, for example, was used in automobile taillights before World War II until plastics replaced glass.