Genuine vs Artificial Sea Glass - Why it's Important

Genuine verses artificial sea glass, How to distinguish real vs fake seaglass. About tumbled beach glass and more.

I purposefully do not call faux sea glass "sea glass" anymore these days. I always make a point of naming it "frosted glass" or "machine tumbled glass" or "man made, frosted glass". To term it 'sea glass' infers that it has spent time at sea. Which it has not.

Manmade, machine tumbled or chemically frosted glass often looks too perfect.

For myself and for most collectors, sea glass is historic glassware and bottles that have somehow reached the sea or body of water.  They have been on a journey that cannot ever be repeated.  Each piece has a story and tale to tell.
The moment sea glass collecting took the spotlight, its value as a commodity to be found, bought, sold and traded increased dramatically.  And just like any collectable that has garnered sudden attention, the adoration caused a bit of a run for buying and selling.

And when any true item becomes of value, a faux or artificial product is not far behind.  Man-made "frosted glass" showed up on the modern market. This mechanically created glass is not  sea glass. Above right, a dusty blue triangle of machine tumbled, faux "sea glass".


Real sea glass is glass that has spent time and a unique journey at sea. It has stood the test of time and tide, often for decades. This is what gives genuine, beach combed sea glass its value and significance. The process of mimicking the forces of nature cannot exactly be duplicated.

Genuine, authentic sea glass is glass (a bottle, a dish, an old window pane) that was once discarded, unwanted, and tossed out to sea as refuse. It may have found its way to the shoreline after being thrown overboard from a ship. It may have been barged out for dumping by a cargo ship. Or it may have been pushed off the edge of a sea shore town's landfill bluff.

No matter how the glass reached the ocean, we are finding that years and decades later, it is turning up along our beaches as gems with smooth edges and a frosty surface. Above left, an ocean tumbled, well frosted cobalt blue shard of genuine, historic bottle glass.

Since mass production of bottles began in the early 1900s, glassware became much more common in the average household and thrown out after being broken or unwanted.


It takes many years out in a natural body of water for a piece of glass to become smoothed, softened, and frosty. That frosty pitted surface is what many sea glass hunters and collectors admire. It cannot  be mimicked exactly by a mechanized process or by a chemical bath. But there are some who have tried to create imitation sea glass.

To the purist, the historian, and the archeologist in all of us, this has become an important issue.


In response to so many questions and inquiries, my colleagues and I combined some  of our genuine pieces from around the country and created part of this article and a photo still life for educational purposes (above right). Our pieces were arranged together on a table and then one member purchased some artificial “sea glass” and posed it next to the pieces of genuine. The groupings were photographed in attempt to help the viewer understand the visual and structural differences between ocean tumbled and machine altered glass. 

The photo shows some of my genuine, ocean tumbled sea glass in the top left triangle of the frame. The more angular, blocky pieces in the bottom right triangle of the image are machine-made, frosted pieces of glass. The faux sea glass has been clouded out in the photo at left.

Beautiful frosting and pitting on a soft blue sea glass bottle stopper top.

If you’re a sea glass enthusiast, it is highly likely that you’ve seen these photos on the Internet and throughout many random blogs. Permission has been allowed for hundreds of members of the  North American Sea Glass Association  to use them for educational purposes.

Some truly mature pieces can be so well rounded and without blemish that they appear more like a marble than a sharp edged shard. This high quality  closeup of a soft aqua blue bottle stopper top, at right, shows clear signs of natural tumbling at sea. But not all beach glass is completely smooth-edged. Some pieces can be sharp and chipped with visible corners and shinier surfaces. This simply means that the piece has not spent enough time being sanded by a shore's wavy, rocky and or salty environment

Notice the frosty patina with microscopic pits and "crescent shaped" marks. These factors are one indicator of naturally conditioned sea glass. A white, sugary frost is also a sign of a piece that has spent time in a natural body of water. In addition, most artificial sea glass shows a creamier, more consistent patina on its surface.

At  West Coast Sea Glass, we go out of our way to remember where each piece was beachcombed and we keep track or our pieces by which body of water it was found along. It matters to the beach lover that their piece is genuine and historic and has been sculpted by the ocean. For more thorough information about sea glass and beautiful photos, get your copy today of the book  "The Ultimate Guide to Sea Glass"  written by  Mary Beth Beuke, Owner Artist - West Coast Sea Glass


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