Thursday, October 16, 2008

Sea Glass vs Craft Glass- A comparision between the "real thing and the imitation.

I've been asked many questions at craft shows and on the Internet about the sea glass. Questions such as, "What makes this a piece of authentic sea glass", "How can you tell that this is craft glass" are my favorite... "Where do you find your nicest pieces"?

I don't consider myself to be an expert in the field of sea glass. Collecting sea glass is a hobby that is shared by my hubby and I , along with our 2 sons. We love the beach and often spend hours on it's shore's, walking in search of what the previous tides may heave left. Our sea glass findings are displayed in the many decorative jars in our home and on the very lucky occasions that one of us find a jewelry quality piece, I'll make it into a handmade CreationsByRobin piece of wearable art.

In recent weeks, I've been asked to "authenticate" a piece of jewelry that someone was wearing and on another occasion, to look over a fellow vendor to authenticate if a piece was sea glass. (In both instances they were not authentic ... though the women who had spent a good deal of $$ on a piece of jewelry was told, we weren't sure)

My hubby has now reached a point that he'll question vendors when he feels that they are selling "craft glass" but selling it as authentic sea glass and he's come to realize that many vendors claim to know very little about sea glass and they know even less about the differences between the two.

Which brings me to the reason behind this blog entry...

How can you tell the difference between beach glass and craft glass?

I'll defer to one of the top sea glass experts to help me explain the subtle, yet often obvious differences. Richard LaMotte, in my opinion, is one of the foremost experts on sea glass. He took a great deal of time to learn from glass makers, chemical experts, etc and wrote a book about his experiences called, "Pure Sea Glass". "Pure Sea Glass" is my sea glass bible and accompanies me to each and every craft show.

I'll be borrowing often from his book in my explanation of the differences.... The biggest difference in sea glass and the one that craft glass makers can not duplicate is the weathering process that occurs to glass in the ocean. The process is called "hydration".

To put Mr. LaMotte's detailed explanation into the shortest terms, while in the water, hydrogen ions replace sodium ions in the glass. This creates a sodium hydroxide which begins to corrode the glass. The corrosion process is assisted by the higher pH levels found in the ocean. This procedure allows the glass surface to become altered and upon removal from the water, the dried surface can often display powdery crystal formations (from the corrosion process)

This process can often take decades to be obvious to the naked eye, but it is possible to feel the "pitting and scaring" of the glass with your fingertips. Mr. LaMotte goes into much greater detail and touches on how glass was made from specific periods of time and the differences to look for in identifying how old glass is.

Mr. LaMotte goes on to state the following about imitation glass (craft glass)..."Most of the imitation sea glass made today has a noticeable silky texture with very little surface pitting other than a uniform haze. Suppliers will often provide warnings regarding handling and use of this glass if it was etched with a strong (hydrofluoric) acid."

He goes on to say that the imitation sea glass is created for use in flower displays or decorative uses, but aren't well-suited for use in aquarium. The hard edges and fracture marks of imitation sea glass can be easily spotted, and the glass lacks the more obvious characteristics of pure, authentic sea glass.

I know that craft glass makers and some jewelers are trying to make headway into the market with less abrasive glass. These attempts are quite obvious to anyone with a basic understanding of sea glass. Because these imitation glass makers are attempting to make jewelry quality pieces, they are unable to use the acids to create an authentic look. Many of the the pieces that I've seen recently look beautiful, but clearly aren't authentic sea glass. They are big pieces, with harder edges and almost no sign of the pitting and scaring that authentic sea glass displays.

These makers sell the fact that the focal point in their jewelry is clean and bright. The piece doesn't show any differently in the light or sun, while an authentic piece of sea glass will brighten when put in direct light (especially sunlight) and often the colors will change dramatically!

Craft glass is what it is and if you want a piece of jewelry that has dazzling color all the time, then a piece of jewelry with imitation sea glass may be for you...just don't pay sea glass jewelry prices (and yes, I know my pieces of authentic sea glass creations are extremely inexpensive...but please don't pay sea glass prices for the imitation : ) )

Authentic sea glass is becoming harder to find. Glass productions nearly came to a halt 40-50 years ago and with the exception of beer and wine bottles, there really isn't much glass production these days... not the kind of production that makes it into the ocean anyway.

Richard LaMotte's book puts it best... "Discovering Nature's Vanishing Gems". If you want authentic sea glass, look for a respected member of the North American Sea Glass Association and for sea glass jewelry, look to the many handmade jewelers, like myself, that specialize in using authentic sea glass and capturing a period of time that will vanish one day very soon!

I hope this answers some questions I've been receiving. Feel free to ask if you have more, I truly love my hobby and just reading up on the weathering process taught me more about how the glass comes to be. Hopefully it will be around for several more years...

I'd hate to think I'll be doing a sea plastic blog in the future : )

'til next time....

PS- obvious pitting, scaring and bubbles (or small Cs) can be seen on and inside the sea glass pictured above. It's this process that imitation sea glass is unable to reproduce.


13moons said...

That's interesting. I didn't know you could really tell the difference. I had no idea there was a chemical change as well as just the abrasion from the glass being rolled and tumbled around in the water and sand for opposed to putting broken pieces of glass in a rock tumbler with the tumbling bits and sand and a little water...which is also a good reuse, recycling of materials, as long as the end product, if it is being sold, is honestly represented.


Debbie Gootter said...

okay- I have always kind of wanted to know this but never looked it up- I have never seen anybody call it craft glass- everybody calls it sea glass whether its' real or not!

v klöch said...

I have diffidently seen some fakes out there. And then there are those who don't even consider it wrong to make the knock-offs. I can't tell you how many people say to me when I tell them that I'm heading down to the coast to look for sea glass, tell me to just tumble a piece of glass myself. OMG, isn't anything sacred? I also highly recommend the book "Pure Sea Glass" too. It really brings appreciation to the natural charm that takes a hundred or so years of natural tumbling made by the ocean to produce these precious little gems. I'm so glad that you have addressed this issue. Looking forward to reading more from this great blog!!