Red Glass: Why is it so special? And, why does it fascinate us?

By Jim Allen

For most of us, spotting a piece of red sea glass is pretty much guaranteed to trigger an endorphin wave. With the increasing rarity of the stuff, it’s a special moment when we beachcombers look down on that piece of crimson joy. Whether derived from an old apothecary bottle, decorative glassware, lanterns, signal lenses or whatever; cherry red, wine red, blood red, ruby red, cranberry red, it makes little difference. We love it all. But, as you’ll see, this fascination is nearly as old as civilization itself and innate in our species.

The history of red glass goes back to Babylon nearly 4,000 years ago. In fact, we have a cuneiform clay tablet from that period, which in very esoteric detail gives the reader a “recipe” for making red glass. Egyptian tombs, Roman rings, and Byzantine jewelry all exhibit red shades as well as the steady progress in the processing of colored glass. As early as ancient Greece, red glass was thought to have magical qualities. Alchemists were convinced that the sorcerer’s stone, that substance by which they believed base metals could be transformed into gold, was of a red glass-like material.

In the 700s, the Persian chemist Abu Musa Jabir ibn Hayyan began cataloging techniques for the making of colored glass. He systematically instructs that oxides of the various metals when added to the glass batch would determine its specific color. Red was ever more favored and by the early Renaissance ruby-red glass decorated royal courts throughout Europe, achieving a status comparable to precious metals and exquisite fine art.

The lower classes experienced red glass in what one might refer to as the special effects of Medieval Europe. These were the magnificent stained glass windows of the great Gothic churches. Window artisans needed a full palette of deep, vibrant colors to depict the scenes (most often from the Bible), which would instruct, inspire, or frighten the faithful. Details of the scenes or persons were painted by employing a paint mixture of ground lead or copper filings, ground glass, gum arabic, wine, or urine (no, that wasn’t a typo).

But early colored glass suffered from a serious flaw: it was found to be lacking color durability. After years of exposure to the sun’s ultraviolet rays, the colors would often fade, darken, or change color. And for some reason, red was especially susceptible to this problem. The solution to making red glass color fast was to add small amounts of gold chloride. Of course, this made red glass the most expensive color and, therefore, assured its relative rarity. For a deep ruby red, the gold content is higher than for the lighter cranberry shade. For the show stopper bright red, selenium is used.

With the publishing of Antonio Neri’s L’Arte vetraria in 1612 and, in the same century, the German glassmaker and chemist Johann Kunckel discovering how to make ruby red glass, we see the manufacturing of colored glass in its many intricate and precise steps finally put on a scientific footing. Instrumentation and knowledge were still far from the level necessary to guarantee consistent outcomes, but great strides were being made.

So why this age old attraction to red? Studies have shown that as infants we seem to show an interest in red over other colors. This preference lasts throughout the preschool period. With maturation, our interest in red lessens, and our preference ends up on the opposite end of the visual spectrum at blue (which is probably why advertising pros tend to frequently recommend red or blue). This seems to be a universal predilection. Nearly 75% of the nations of the world have included red in their flags. Of course some accepted notions about red may not always be true. You’ve no doubt heard that red excites us or actually increases aggressiveness. Researchers are not so sure. These old saws are still hypotheses, which when actually tested, are usually inconclusive.

But when we feel that what we wish to communicate is truly important, we go to red. Red banners have been flown by revolutionary movements for centuries. Red is generally the color used to warn of danger: brake lights have been red for a hundred years and became the internationally agreed upon color in 1949. Red “Do not enter” and “Stop” signs are also universal as is the red circle with the diagonal through it. Navigators pay strict attention to the red buoys for fear of running aground. Until recently, all fire engines were, well, fire engine red.

We may never know why the Little Red Corvette, the Red Carpet, a Red Flag, The Red Light District (each country has its own explanation for that), Seeing Red, or countless other expressions chose this wonderful color. Somehow or another, when the rods of our retinas are excited by the frequency on the lower end of the visual spectrum, i.e., red, it arrests our attention.

And on a blustery winter morning when the sea is whipping its bone chilling salty spray at us and showing little patience for us beachcombers, doesn’t snatching up that coveted little piece of red, as a big grin crosses our briny face, just confirm that red glass still fascinates us after 4,000 years? 

This article appeared in the Beachcombing Magazine July/August 2020 issue.

Red sea glass is a rare and special find

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