Sea glass sometimes referred to as mermaids tears, is the name given to glass from any source which ends up in the oceans of the world. It consists of pieces of glass which have been discarded and broken by currents, tides, and wave action.
Most sea glass comes from bottles which have been thrown into the sea or included in the garbage which was dumped into the ocean. Some sea glass originated as parts of fishing equipment (glass floats were used to support large nets), lenses from navigational lights, even auto and truck lights, and virtually anything which was constructed to include glass, including insulators seen on older telephone poles.
The natural action of waves, combined with the ever-present sand, over time, causes a smoothing of the edges. This, along with the salinity, which varies from ocean to ocean, ultimately leads to the chalky patina found on older glass. Experts have concluded that it takes a minimum of thirty years for an average piece of sea glass to acquire the rounded shape with smooth edges and the characteristic patina.
Beaches on which sea glass is found are usually located near a city which discarded its trash into the sea. The currents can move sea glass large distances. Rocky areas cause the glass to be broken into unusual shapes with thicker glass, such as found on the bottom of certain bottles, to be the larger pieces found. It’s not unusual to find shards of pottery along a beach where sea glass is plentiful.
Sea glass is in short supply and becoming harder and harder to find. This is due to the prohibition of dumping waste into the ocean, commonly done in the past. Also, the manufacturing of plastic, especially in bottles, has further led to diminishing quantities.