Sea glass

Sea glass and beach glass are similar but come from two different types of water. "Sea glass" is physically and chemically weathered glass found on beaches along bodies of salt water. These weathering processes produce natural frosted glass. "Genuine sea glass" can be collected as a hobby and can be used to make jewellery. "Beach glass" comes from fresh water and in most cases has a different pH balance, and has a less frosted appearance than sea glass. Sea glass takes 20 to 30 years, and sometimes as much as 50 years, to acquire its characteristic texture and shape. Sometimes also colloquially referred to as "Drift glass" from the longshore drift process that forms the smooth edges.

Sea glass begins as normal shards of broken glass that are then persistently tumbled and ground until the sharp edges are smoothed and rounded. In this process, the glass loses its slick surface but gains a frosted appearance over many years.

Naturally produced sea glass ("genuine sea glass") originates as pieces of glass from broken bottles, broken tableware, or even shipwrecks, which are rolled and tumbled in the ocean for years until all of their edges are rounded off, and the slickness of the glass has been worn to a frosted appearance.

Artificially produced sea glass (sometimes called "beach glass"), although superficially similar to sea glass, nevertheless has clear differences in appearance. Having not actually originated from the sea, most connoisseurs will not consider artificial "sea" glass to actually be genuine sea glass, but rather simply tumbled glass, where pieces of modern-day glass are tossed into a rock tumbler or dipped in acid to produce the desired finish. Artificially-produced, the glass is much less expensive and is used for making jewelry, but is often passed off as real sea glass.

Sea glass can be found all over the world, but the beaches of the northeast United States, Bermuda, Fort Bragg, California, Benicia, California, North Carolina beaches, Scotland, northwest England, Mexico, Hawaii, Dominican Republic, Puerto Rico, Nova Scotia, Australia, Italy and southern Spain are famous for their bounty of sea glass, bottles, bottle lips and stoppers, art glass, marbles, and pottery shards. The best times to look are during spring tides especially perigean and proxigean tides, and during the first low tide after a storm.

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Wikipedia