How Sea Glass Is Made in the Ocean

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“Things perfected by nature are beter than those finished by art.”–
Marcus Tullus Cicero

The Serendipity of Sea Glass

Many sea glass collectors believe that sea glass is more valuable than precious gems. Several crafters use sea glass to make beautiful jewelry and other crafts. People even spend money to buy sea glass, especially the rarer shapes and colors like orange, red, pink, yellow, turquoise, cobalt blue, and sea foam.

Who would have thought that the ocean could take dumped trash, tumble it around in water and sand for decades and push it back onto the shore in spectacular thick, frosty and rounded gems.


How is Sea Glass Made?

How Sea Glass is Made in the Ocean


It’s Not Just About the Surf and Sand

It’s not just the pounding surf against the sand that turns discarded glass into sea glass, as many people believe–although it is a factor. According to Richard LaMotte author of Pure Sea Glass, “Significant abrasions also come from aggressive lateral movement of the glass within the littoral zone, just offshore.” Strong currents along with wave action, increase the “overall etching of sea glass.”

The high pH saltwater levels in oceans and estuaries also affect how sea glass is made. The pH level increases the weathering process by dissolving the silica structure of glass. High levels of carbon dioxide in seawater also increase the weathering process of sea glass, says LaMotte.

Many more things such as the ingredients of the glass, the location where it was dumped, the movement of the water, and the time it spends in the ocean affect how sea glass is created in the ocean.

How Sea Glass is Made in the Ocean


Sea Glass Identification Tips

One cannot help wonder when he or she finds a piece of sea glass where it came from. How old is it? What was it used for?

While it’s nearly impossible to find out exactly where and what a piece of sea glass came from and how old it is, it is possible to get a general idea.

  • Most sea glass comes from bottles, especially after the Owens automated bottle machine was invented in the 1920s.
  • Rare colors of sea glass, like pink, aqua, cornflower blue, white opaque, citron, and purple often come from tableware.
  • Bubbles inside sea glass typically suggest it’s an older piece of glass from the 1700s to the 1800s before the automation of glass. The more dense the bubbles are, the more likely it’s an older piece that’s been tossing around in the ocean for a while. 
  • Thicker shards of sea glass are often older pieces too.

The unique journey and transformation of sea glass make sea glass collecting one of the most popular activities in the world. Its beauty also makes sea glass one of the most sought after gems by jewelers and craft creators everywhere.

The Process of Making Sea Glass


LaMotte, Richard. Pure Sea Glass.



  • I am trying to start a webpage to show and hopefully sell some of my sea glass designs. I LOVE your descriptions of sea glass and especially what you wrote about “Serendipity” of it. I was wondering if I could Quote you? I will give you full credit of course! If given permission.


    Amylynn Prouty

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