North Beach Treasures: Natural vs. Man Made Seaglass
North Beach Treasures
Copyright© 2006-12 by North Beach Treasures & Peter Messerschmidt, All Rights Reserved

Authentic Beach Collected Sea Glass, Pottery and Artifacts from the Pacific Northwest
The Issue of Natural vs Fake ("Man Made") Sea Glass

Within the growing sea glass collector and jeweler community, there is much controversy over-- and discussion of-- the growing issue and problem surrounding so-called "man made" sea glass.

The situation: There are companies (and individuals) that will manufacture "sea glass" by putting shards of broken glass into industrial rock tumblers; basically huge versions of what rock hounds use to polish rocks. The result is something that looks like sea glass, but really isn't... since it has never been in the sea, to begin with. Until recently-- because seaglass has only enjoyed such a surge of popularity during the past 5-odd years-- this type of "craft glass" was never really seen as much of an issue to worry about.

It does take a fairly skilled eye and some experience to tell fake sea glass from the real thing, but there are subtle differences between the two, most of them relating to coloration and surface texture-- what sea glass enthusiasts call "frosting."

One important thing to keep in mind is that most beach combed seaglass is quite scarce-- especially in certain colors and shapes-- and thus should not be confused with the glass that can be bought in 5-pound bags at hobby and craft shops. In most cases, it would take a beach comber weeks, if not months, to collect five pounds of genuine surf tumbled beach glass!

Genuine sea glass can be quite rare. In my travels around eBay and the greater Internet, I have come across a number of "superb" and "rare" sea glass items that have sold for more than US $200.00 for a single piece. As of this writing (May 2011), the highest price I have seen for a single piece of sea glass auctioned on eBay is US $417.00 for a large, flawless and perfectly frosted cobalt blue bottle stopper. That's an exception, of course, but nice pieces of orange sea glass (widely regarded as the rarest color) routinely sell for US $50.00 per piece, and more.
With "the real thing" commanding such prices, it's easy to see why it's extremely important to be able to tell man made craft glass from genuine sea glass. Here are a few tips:

Authentic sea glass (or "beach glass") is typically the result of discarded glass objects finding their way into the ocean, getting broken, and then slowly getting polished by the motion of waves, sand and pebbles, in a process that can take 30-40 years or more. Where I beach comb, I can sometimes determine that a piece of glass I have found is over 100 years old!
Such discarded glass (literally garbage) is fairly random in nature, and this offers one clue to recognizing genuine sea glass. A handful of craft glass is typically all the same color, hue and intensity-- you can tell it all came from the same place. Genuine sea glass? Came from a myriad different sources, and so a handful of "the same" color will actually have lots of different shades, subtle color variations and so forth.

Note also that genuine sea glass will have many different thicknesses-- generally, craft glass will be fairly uniform in thickness, since it typically came from very similar broken bottles.

The surface "texture" is also very important. Genuine sea glass has what collectors call a "frosted" surface-- and this is also highly prized. This frosting is the result of a very slow creation process that involves time, salt water, sand and rocks, and the wear on any given piece is not necessarily even. Manufactured glass tends to have a very uniform "satiny" surface-- often the result of acid etching, which attacks every surface of an object equally.
I want to return to "frosting" for a moment, as it is such an important word, in describing authentic sea glass. The surface of a piece of genuine beach combed sea glass looks almost "dusty" or "sugary," like the surface should feel powdery to the touch.

Under very close scrutiny, you'll be able to detect very tiny "C" shaped marks on the surface of the glass-- an effect that simply cannot be reproduced in an artificial environment. What you are looking at is actually the result of a chemical reaction between glass and water-- and it takes years (20+) to create.

Sea glass frosting is most pronounced on glass collected on the shores of salty bodies of water with rough surf, such as the Atlantic and Pacfic coasts. Frosting is less pronounced on glass from brackish calm waters and protected bays, and even less so when the glass comes from freshwater sources like lakes and rivers, where the environment is often muddy, rather than sandy.

If you are purchasing sea glass from a source on the Internet, it always pays to buy from a reputable dealer, even if the price is a little higher.
A handful of genune pastel green sea glass. Note the vari-
ations in both color and thickness.
Extreme close-ups of the surface of 3 pieces of genuine sea glass. The crescent shaped mark on the piece at right is an extreme example of the "C" shaped marks on authentic sea glass.