Genuine vs. Fake Sea Glass

Beautiful—and genuine—sea glass from coastal California

As sea and beach glass becomes more and more a "vanishing gem," it was only inevitable that fake glass would make an appearance. It’s been around for a while, used mainly as home décor and aquarium filler, and marketed as such—imitation sea glass. Beachcombers haven’t any issue with these products, and are appreciative of the honest marketing/labeling.

In the past several years as the popularity of sea glass collecting increased, and thus the plentiful-ness of sea and beach glass decreased, people have looked to capitalize on both these aspects by creating glass that appears to mimic actual sea glass. At best, the offerings are wannabes only, as the true beachcomber can usually immediately spot the imposters. It will anger most genuine collectors and certainly the artists; imagine stumbling upon a booth at an art fair, filled with what’s touted as genuine sea glass jewelry, when you know—even from a distance—that it is indeed, manufactured. Because manufactured glass almost always uses the ‘rare’ sea glass colors, it cheapens the glass the true artists do employ, those people who have spent so many hours and days upon the beach, combing for their treasures, happy for those rare small chips of the most elusive colors.

Pitting caused by a chemical reaction between the pH of the body of water and the ingredients of glass, cannot be duplicated in manufacturing.The differences are plenty, but not often so apparent to the average or casual beachcomber. It is impossible in manufacturing to replicate exactly what the ocean or lake or river does to the glass to make it "sea glass." Most believe that sea glass is borne of wave and sand tumbling alone, and though this is false, it is the most commonly used method of creating faux beach glass. However, the water itself, the pH of the water—higher in the ocean, lower in lakes and lesser bodies of water—is the most important component of the sea glass journey. There is an actual corrosion that takes place between the glass and the pH of the water; the higher the pH, the greater, and possibly quicker, the corrosion.

Hence, true sea glass is actually a physically and chemically weathered remnant. The corrosion is a process of hydration. Minerals within the water react with the soda and lime that was used to make the glass; the soda and lime are slowly filtered out of the glass, leaving microscopic pitting, mostly in the shape of a small crescent, or "c," which is impossible to duplicate with artificial sea glass. That telltale "c" is visible to a very strong naked eye, but better seen with enlargement.

Artificial—or manufactured—sea glassFake sea glass is often found to be thick and chunky, with betraying cut marks where a machine has broken the glass. It will not have the proper frosted appearance to signify its time in the water. Genuine sea glass is mostly found to be triangular in shape, and not uniform at all (just ask a sea glass jeweler looking for matching earrings parts), though sometimes glass from deeper water, that was older (and likely thicker) and survived longer will have a rounded or bulbous shape. You will not find these same shapes in the fake stuff.

The man-made sea glass, lacking the proper ocean frosting, will be shiny and smooth to the touch, almost like a polished piece of new glass. Authentic sea and beach glass will have sometimes uneven, but smooth edges; the fake pieces are usually rough and often too straight cut, and very often found to be square shaped, as you so rarely would find in real sea glass. If you come across a ‘batch’ of glass that seems to be all the same size shape and size, this uniformity is a telling sign of faux glass. While every sea glass artist might dream of such consistent quality in the glass they find, the purist in them won’t allow them to stray from the unadulterated sea glass.

Faux sea glass made via an acid bath leaves a telling residueFor the consumer, any red flag that accompanies the sight of ‘too perfect’ sea or beach glass should be well heeded. Fraud does exist, purveyors will lie to your face and tell you they beachcombed themselves for the pound of red glass they’re trying to sell you for $10—another significant clue that it’s fake, an unheard of low price for a piece or a pound of one of the rare colors.

In the end, of course, there’s nothing that can be done to prevent them from making or selling the faux sea glass, nor to avoid all contact with it. The educated beachcomber or buyer will know—or research—the truth. Beautiful—and genuine—sea glass from coastal California. Artificial—or manufactured—sea glass. Note the lack of "frosting" which can only be achieved over many decades as a chemical reaction in water. Also, there is no variation in thickness, though genuine sea glass will come in many shapes sizes, and thicknesses. Microscopic view of sea glass. The "pitting," caused by a chemical reaction between the pH of the body of water and the ingredients of glass, cannot be duplicated in manufacturing. Above, an attempt at making faux sea glass via an acid bath, but it leaves a telling residue.

This article appeared in the Glassing Magazine July 2017 issue.

5 Tips for identifying fake sea glass and beach glass


(Continued…) Honest sellers base prices on rarity and quality. Some beaches are difficult to reach, or the rarity of the glass, i.e a marble or a stopper.

Elizabeth January 07, 2024

I’ve seen several sea glass sellers post a picture of genuine sea glass z sale, but sent the purchaser obviously fake sea glass. The glass was as thin or thinner as tortilla strips and were much too evenly frosted.

What I wish is that the mega-hoarding of sea glass would stop. I’m not talking one bag, but the people who carry several bags (trash s are leaving very little to none for visitors and kids new to collecting.

I looooove sea glass, but knowing how much is hoarded, and having the nerve to sell one piece for $55.00 or more, especially when the same piece sold for $20.00 only two years ago, and $12.00 seven years ago. Not all sellers do this, and many base the price

Elizabeth January 07, 2024

Hi, Jan! You should try a rust remover. Soaking the pieces overnight should help to take off any of the rust stains. Unfortunately, tumbling them removes the beautiful patina found on unaltered sea glass. Good luck! Kirsti

Kirsti Scott January 14, 2022

Interesting article. I love sea glass hunting. My finds around the Bay of Fundy area of Eastern Canada have a yellow stain on them. (All the white pieces – the greens and browns, etc don’t show the stain). Bleach, scrubbing, vinegar and soda water do not clean it off. Found out it was the iron content in the water. I have tried tumbling with a little grit for a few hours and it cleans off the stain. The stain is so bad it camouflages the true beauty of the piece. Are these pieces now considered manufactured? They are old thick pieces that are hard to find anymore.

Jan Stoutamire January 14, 2022

Ryan, you can find several on Facebook. You just need to join a few sea glass aution sights and most people there can tell you a good one.

Heidi November 05, 2021

I found this article very interesting. As a sea glass jeweler myself, I am constantly running across phony sea glass jewelry at craft shows and in shops. Like you said, as long as the seller is honest and informs the customer that the " sea glass" they are selling is, actually man- made, I have no problem. However, this is rarely the case.

It’ s the difference between a cubic zirconia and a diamond *.
Tammy April 13, 2021

Where do you find a " Sea glass jeweler ".

Ryan October 06, 2020

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