That soft, subtle glow that we all love about fine quality pearls is unmistakable and highly prized. It is created when nacre reflects the light. But most people do not fully understand what nacre is or why it is important to consider when buying pearls. Here we dive deeply into the definition of nacre and explore how different types of pearls create different types of luster.

What is Nacre? Definition & Science

Nacre (pronounced NAY-kur), quite simply, refers to what is more commonly known as mother of pearl. It is the precious material that forms the bulk of most pearls – that beautiful, strong, radiant substance that gives the pearl its beloved and enduring luster.

Scientifically, nacre is the inner iridescent layer of oyster shells which is composed primarily of aragonite (a form of crystalized calcium carbonate) and conchiolin. Conchiolin is a tough insoluble protein secreted by mollusks forming the shell within which calcium carbonate is deposited. An oyster, when creating a pearl, alternates brick-like layers of aragonite with a film made of organic material. According to Harvard University, that layered structure is why nacre is “a material of extraordinary strength.” 

A pearl forms inside an oyster by a natural process in which the oyster secretes layers of nacre that wrap around a foreign object, or, in the case of cultured pearls, a nucleus that has been inserted specifically for the purpose of cultivating a pearl. These layers produce the eventual thickness of nacre in the pearl. The more layers of nacre, the higher the luster of the pearl.  Or in other words, the thicker the nacre, the better the luster.

Luster of White Pearls – South Sea & Akoya

White pearls are more likely to produce a mirror-like nacre, simply because of their color. White pearls produce a more recognizable mirror-like nacreous surface. An evenly white, cream, or silver-white saltwater pearl has a more obvious and even luster, which is the reason they are known to light up a complexion of any color.

White South Sea pearls (along with golden South Sea pearls) are known to have the thickest layers of nacre of all the cultured saltwater pearl types. Assael’s South Sea white pearls come primarily from the northern coast of Australia where the climate is highly conducive to pearl cultivation. Nearly 60 years of sourcing pearls from this area has helped Assael to amass a collection of some of the most highly prized pearls in the world.

The Akoya pearl is a white saltwater pearl known for having the highest luster of all cultured pearls. Being born in Japan from a smaller oyster, hence a much smaller average size, the cooler temperatures of the water there reduce or slow the rate of nacre secretion in the oyster, making the nacre more compact and denser. This creates superior reflective and refractive qualities in Akoya pearls, and thus, higher luster.

Assael boasts an unrivaled inventory of Akoya pearls, along with a step by step pearl necklace builder to help pearl fans select the perfect size, style, and length of a forever strand of Akoya pearls.

Luster of Tahitian & Fijian Pearls

The nature of Tahitian and Fijian pearls, which often have undertones of one or more colors, affects the luster. These colorful and multi-tone pearls can have high, medium, or low luster, like other pearls. Fine luster in a Tahitian or Fijian pearl accentuates the color and creates a soft metallic look.

A single, even color of a pearl helps the eye to look at the entire pearl; whereas a multi-hued nacre causes the eye to look in specific places on that pearl. An example – the more times you look at a multi-toned Tahitian, the more likely you are to see the various colors. This is one of the reasons that Tahitian pearls are so incredibly mysterious and alluring. They also make for creative and wonderful jewelry designs like those found in Assael’s “The Colors” collection which pairs colored gemstones with pearls in unique and complementary ways.

Luster of Golden South Sea Pearls

South Sea pearls (both Golden and White) have the thickest layers of nacre of all the cultured pearl types. The luster of South Sea Golden pearls radiates like sunshine. It has a buttery, golden hue. It is less mirror-like because it is not white; however, the sunny iridescence is truly beautiful and preferred by some. The deep luster formed by the thick layers of nacre secreted by the oysters in The Philippines and Indonesia envelops the eye in warmth, similar to rays of sunlight that peek over the horizon.

With the deepest, richest golden hues of the South Sea range, Assael South Sea Golden pearls have a luminosity and warmth that exudes grace and elegance. These natural color golden gifts from the sea make a cherished addition to every pearl lover’s wardrobe.

Dimensionality & Depth of Luster

When shopping for pearls, always look for the highest luster that you can afford. Look beyond the surface to discover depth and dimensionality. Multidimensional glow in pearls is much more refined and treasured. Dimensionality of luster only occurs in fine quality saltwater pearls which must stay in the ocean water for longer periods of time. These pearls take longer to form than their thinly coated cousins in freshwater lakes and rivers. This accounts for a significant part of the price difference between fine pearls and those that are not.

Lower priced freshwater pearls have a thin, mirror-like coating of nacre. But once your eye becomes accustomed to looking at luster, you will more easily recognize that most freshwater pearls do not have a multidimensional glow, the very reason that pearls have been so sought after throughout the ages.

To sum it up – more than anything, nacre is all about luster. The deep, dimensional luster in fine saltwater pearls can be mesmerizing, even breathtaking. It lights up your skin like nothing else. Experiment with different colors of pearls to enjoy and appreciate the various types of luster. Look deeply into your pearls to get lost in their magnificence. And visit Assael.com frequently or follow us on Instagram to see what new designs we have created using your favorite type of pearls.

Feature image at top – clockwise from upper right – Tahitian Bubble Earrings by Sean Gilson for Assael , Assael South Sea golden pearl and bi-color tourmaline ring in 18K gold with pink sapphires from The Colors collection, Assael strands of pistachio and eggplant Tahitian pearls, loose South Sea pearl with multidimensional luster 

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