How to Identify Black Sea Glass

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Many experienced sea glass collectors will say black is one of the most difficult pieces to find. Besides the odds being about 1 in 2,000 that you’ll find one, black sea glass is also more elusive because of the challenge to recognize it lying on the shore among dark rocks.

Black Sea Glass Collecting

Most sea glass collectors covet black shards because of their scarcity, and because black glass has been produced in limited amounts in contemporary times, much of the black sea glass lying on the beach is decades to hundreds of years old.

Black Sea Glass


The Beauty of Black

Most black sea glass is not black. Rather its true color is a dark, olive green or dark amber. When it’s dry, it looks black.

The beauty of black sea glass is not only its color, it’s also its rarity and its historical significance. Most black shards are found in the Caribbean and other older historic sites where the liquor trade was common during the 18th and 19th centuries.

Black sea glass in the sun


How to Find Black Sea Glass

To find black sea glass look for dry stones that are frosty and chunky. Then wet them and hold them up to the sun or use a bright flashlight to inspect them for a dark green or dark amber ambient glow. If you suspect a wet shard lying on the beach is black sea glass, hold it up to the sun or a flashlight too, and look for the ambient colored glow. Sometimes, the shards are so dark they only show their true color around the edges.

The Different Colors of Sea Glass

One of the best places to find black sea glass is in Fort Bragg, California. Glass Beach in Fort Bragg is famous for its abundance of sea glass. It’s considered to have the highest concentration of sea glass in the world. Much of the glass was dumped into the ocean in Fort Bargg from 1906 to 1967.

Glass Beach Map and Directions


found black sea glass


Wet Black Sea Glass

Dating Black Sea Glass

Black glass bottles were mainly used during the 1700s and 1800s for liquor and medicine containers. The dark colors protected the contents from sunlight. Between the late 1870s and 1930s a limited amount of tableware, perfume bottles, and buttons were made from black glass.

Black glass was also popular briefly during the art-deco period in the 1950s.

Most older black shards as well as other rare and different colored sea glass tend to be thick because glass before the automation of glass production in the early 20th century was thicker than contemporary glass.

Black like most other older sea glass can also be dated by examining the internal and sometimes external bubbles or “seeds.” The denser the bubbles, the more likely a shard, especially black, could be older and even possibly from the 1700s.

black sea glass



Google Images: Antique Black Liquor Bottles

LaMotte, Richard. Pure Sea Glass: Discovering Nature’s Vanishing Gems.