Sea Glass Primer


Sure, you've collected it your whole life, but how much do you really know about sea glass?  

1.) Sea Glass and Beach Glass Are Not the Same Thing

A gorgeous handmade ring by Leslie Freeman, made with sea glass from the oceans of Martha's Vineyard.

A gorgeous handmade ring by Leslie Freeman, made with sea glass from the oceans of Martha's Vineyard.

While many people use the terms "beach glass" and "sea glass" interchangeably, the experts differentiate: "sea glass" refers to that glass which has been battered by the sea. "Beach glass" refers to that collected from freshwater bodies, which lacks the frosted patina of sea glass. While both types are worn by water, rocks, and currents, the salt in seawater slowly dissolves the glass, leaving the whitened effect seaside collectors know well. (Learn more.)

2.) All Sea Glass Is Litter

In days gone by, sea glass was called "Mermaid's Tears"--believed to be shed for fallen sailors--but actually, sea glass is formed from household and industrial waste (glass bottles, housewares, and the like). While some sea glass may descend from sunken pirate ships and shipwrecks, most sea glass was formed from rubbish thrown into the sea, most is simply rubbish that was dumped in the sea. More restrictive disposal policies and a general desire to reduce pollution has limited the volume of  sea glass that washes ashore in recent years.

3.)  The History of Sea Glass is in its color

The sea glass collecting elite are experts in history.   They research early 2oth century tableware patterns to place a shard's origin in history. They are familiar with the chemistry of glass-making and changes to production recipes. They study maritime history, tides, and wind patterns to anticipate when and where a vintage cache might wash ashore. These experts do all this, plus snorkel, kayak, and repel to hidden beaches to collect those rarest of samples.

A guide to the major groups of sea glass shared by

A guide to the major groups of sea glass shared by

A piece of sun-darkened amethyst sea glass.

A piece of sun-darkened amethyst sea glass.

Part of the reason expert collectors get so excited about shipping lanes and disposal practices is that exceptional, rare samples are worth tremendous personal and commercial value. Some colors--like brown, (beer bottle) green, and white carry the least market value. These colors are still in production and are very common to find.  Seafoam green pieces are less common, generally remnants of soda bottles produced in the 1920s. "Black" samples are rare due to their historical nature. (Black samples are usually dark green or olive color, not true black.) They are often remnants of whisky bottles or ink bottles from the 17th and 18th century. Some recently discovered pieces were from a cargo ship wrecked in the 1770s.  Orange sea glass is considered the rarest prize, as orange glass is fickle to make and has never been industrially produced. Understanding the history of glass production can help you guess when that sea gem you've found made its way into the sea. (Learn more.)

4.) Sea Glass Changes Color

Clear glass that was manufactured in the early 20th century may have a lavender or amethyst hue now. This is because the clarifying agent used to produce a clear effect in the glass darkens with exposure to sun. All those years in the surf and sand would have darkened the sample to the lavender or amethyst color it is today. (Learn more.)

5.) Sea Glass Can Be Pricey

The definitive guide to your sea glass collection.

With samples becoming scarce, and the popularity of sea glass jewelry, an extraordinary piece of sea glass can go for hundreds of dollars. The "Shard of The Year," selected by the North American Sea Glass Association, was awarded $1000. Color, size, and patina all effect the value of a sample. Maybe it's time to check your stash for those rare pieces. (Learn more.)

To identify the pieces in your collection, take a look at curator extraordinaire Mary Beth Beuke's definitive guide, aptly named The Ultimate Guide to Sea Glass.  There you will find historical information, dating strategies, and much more.

Let us know what you discover!


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