We are both surprised and delighted by what is known as iridescence when an angle of illumination changes, revealing to us unexpected shifts in color.
This natural phenomenon is observed in what may otherwise be the monotony of the everyday -- soap bubbles as they float skyward, the hard shell of a black beetle creeping along, the wings of a butterfly perched on a flower, a slick of oil on the asphalt, and the nacre on the inside surface of a shell.
Nacre or mother-of-pearl, is one of nature’s many lessons, designed to be a reflection to us of how to live well.
When an foreign object enters a shell, a nacreous substance encircles it, covering in in layers of nacre over time. Ultimately, the accumulation of nacre results in a pearly, rainbow-colored surface inside the shell. And if we’re lucky enough, it leaves us with a lustrous, iridescent pearl.
Nacre shows us that something unexpected, something unwelcome, can become one of our most precious pearls. Mother-of-pearl is made incredibly resilient by both time and layers. And while it is strong, nacre presents us with a subtle iridescence that radiates light and life.
The term iridescent comes from the word Iris, the Greek goddess of the rainbow. And in mother-of-pearl, the colors of the rainbow are reflected back to us, in the same way they surprise us as in glimpses of weightless soapy bubbles catching the light.
Mother-of-Pearl Across Cultures
“Since the Middle Ages, designers have experimented with ways to achieve an iridescent effect on the surface of glass and ceramics and incorporate naturally iridescent materials such as mother of pearl into their jewelry and metalwork.” - cooperhewitt.org
The purpose of naturally occurring Nacre is to protect and defend the inside of the shell. And as such, artisans have chosen this substance as a medium for design due to its strength and durability.
In collections across the world, you can find mother-of-pearl adorning artifacts such as intricate inlays from as far back as Mesopotamia in 2600 BC, 13th-century medieval Iranian stoneware, 15th-century European small reliefs, 18th-century German snuff boxes, the jewelry of today, and more.
Iridescent mother-of-pearl was used to honor royalty in ancient Mesopotamia and was more recently traded by Native Americans throughout the Southwest United States. The Australian Aboriginal people also have a rich and storied history rooted around nacre.
“To the Saltwater people of the northwest, the brilliance and shimmer of the guwan is considered to reflect water and the sea. Carving guwan into riji is regarded as a boost to an individual’s spiritual well-being and expresses connection to country and ancestors. The wearing of riji often marked the transition to adulthood.”
A brief foray into the history of mother-of-pearl across the globe will undoubtedly reveal two things: nacre is regarded as spiritually powerful and has made a lasting impact on design.
Iridescence and Pearls
Officially the world’s oldest gem, pearls take their place in this history of power and impact.
While nacre may be harvested from the inside surface of a shell, more often we look to pearls themselves as representatives of the process. Pearls are iridescent. But to be more specific in our language, pearls are pearlescent.
Pearlescence refers to the luster that presents itself when all of the light refracted back is white.
Pearls are absolutely iridescent. The round nature of a pearl creates a convex mirror, allowing light to reflect off its never ending surfaces. And the multiple layers of nacre create an alluring iridescence.
In radiating her natural light, the pearl has existed at the center of art & culture for centuries. And now, it is our turn to create our own story around nacre’s iridescent layers of strength and beauty.