What Is Mother of Pearl?

Mary McMahon
Mary McMahon
Mary McMahon
Mary McMahon
Abalone buttons.
Abalone buttons.

Mother of pearl, also called nacre, is an iridescent layer of material that forms the shell lining of many mollusks. Pearl oysters and abalone are both sources of this substance, which is widely used as an inlay in jewelry, furniture, and musical instruments. Mother of pearl comes in several natural colors, but is often bleached and dyed for decorative use. The dye retains the shimmering layers which make the material so sought after. Nacre is a tough and resilient material, but it is relatively soft and easily scratched.

Formation

Abalone shells.
Abalone shells.

Two substances, one mineral and the other organic, combine to create mother of pearl. Tiny hexagonal plates of aragonite, a form of calcium carbonate, are arranged in layers alternating with conchiolin, a flexible protein similar to silk that is secreted by the mollusk. Aragonite on its own is very brittle, but combined with the protein it forms a strong, flexible material that can withstand hard use.

Mother of pearl bracelet.
Mother of pearl bracelet.

The mollusk first of all secretes a layer of conchiolin. Aragonite crystals then form on this surface at numerous points, growing until they meet each other to form tiny plates. A further layer of protein is then deposited and so on, so that over time, many layers build up.

Properties

The resilience of mother of pearl comes from its layered structure and the contrast in properties between the mineral and organic layers. The aragonite consists if hard, brittle crystals, while the organic protein layers are a natural polymer that is flexible and resistant to fracture. The aragonite gives relative rigidity to the material and the protein counteracts the brittleness of the aragonite by preventing the spread of fractures. The result is a natural product that is tough and resilient. As of 2013, research is underway into the manufacture of synthetic nacre.

Abalone shell.
Abalone shell.

Mother of pearl has a hardness of about 3.5 on Moh’s scale. This is quite soft compared with gemstones and most metals. Although its relative softness makes it easy to work with and cut into shapes, it also means that nacre objects can be easily scratched by other items of jewelry, for example.

The iridescence that makes nacre so attractive results from the fact that the aragonite crystals have a range of thicknesses that are close to the wavelengths of visible light. Some of the light that strikes the crystalline layers will go through to the layers below, while some is reflected from the upper and the lower surfaces. Layers tend to reflect particular wavelengths, that is, colors, depending on their thickness and on the angle of the light. When viewed from different angles, different colors are reflected. Small irregularities on the surfaces make every piece of nacre unique.

Function

Mollusks create mother of pearl to protect themselves. In addition to forming part of the shell, it also insulates mollusks from bacterial infection and parasites. Another function of this substance is to reduce irritation or damage from material such as sand or grit that drifts into the shell. The particle is gradually surrounded by layers of nacre, rendering it harmless. This may result in a blister-like irregularity on the inside of the shell, or it may create the unattached, spherical structure that is much prized by humans as a pearl.

Uses

The pearly lining of mollusk shells has long been noted by people living near the ocean. Many early cultures used it extensively in jewelry and it came to be highly prized. Although not as popular as it once was, many modern cultures still appreciate its beauty and mother of pearl continues to be used in jewelry, ornaments, furniture inlays and musical instruments. Some homes integrate it into tiles and other fixtures, although it is no longer used extensively.

Like other substances found in nature, mother of pearl develops irregularities as it forms. As a result, every piece of jewelry or inlay is slightly different, a fact that can add to its appeal. Artisans may work with the unusual features of a specific piece to highlight them. These irregularities may also appear in cheaper jewelry that is not as meticulously constructed.

Nacre has been much studied by scientists interested not only in its strength and durability, but also in what it can tell them about the conditions in which it formed. The thickness and structure of the layers secreted by marine mollusks depends on the temperature and water pressure. It is therefore possible to obtain valuable information about past conditions from the study of fossilized material.

Care

Mother of pearl items should not be stored with anything that might scratch them. They should be cleaned with mild soaps and water; harsher cleaning agents may react with the aragonite, especially if they are acidic. This also applies to pearls, which have an outer coating of nacre.

Where Does Mother of Pearl Come From?

Mother of pearl comes from certain mollusks, including oysters, mussels, and abalone. Mother of pearl is a biomineral, which means that it forms by way of another organism. In this case, it is the product of secretions of a mineral blend that the mollusks make called nacre. Nacre is a material comprised of calcium carbonate and is often used synonymously with mother of pearl.

Nacre

Nacre is what creates the iridescent, oil-slick-like quality inside mollusk shells. The lustrous material isn’t just pretty; it is functional. Nacre also protects the soft tissues of the mollusk inside from debris, parasites, or damage and makes up the outer covering in round pearls.

The defense mechanism traps things in its layers as the nacre is deposited. Once stuck, more layers pile on as the process continues. The resulting layers have different results depending on the mollusk and how long the cycle continues. Mother of pearl forms due to layering, while nacre blister pearls arise attached to the inside of shells, and free pearls will form in the mantle tissues.

What Colors Are Mother of Pearl?

Thanks to the iridescent nature of mother of pearl and how the layers of nacre allow light to reflect and refract, the wide range of colors can be mesmerizing. It is likely for this reason and the apparent connection to the sea that many people find mother of pearl to have calming properties that support intuition, creativity, and acceptance. Some of the most prominent colors found in mother of pearl include:

  • Purples
  • Silvers
  • Bronzes
  • Greens
  • Blues
  • Pinks
  • Blacks
  • Bleached with muted whites and creams

What Is Mother of Pearl Worth

It used to be that mother of pearl was widely traded and used in many different applications. Jewelry with mother of pearl was typical. Seaside dwellers and beachgoers alike would collect abalone and craft it into inlay for various items. Mother of pearl was a trendy embellishment from tiles to brushes to earrings to guitar necks.

Although it has not disappeared from fashion entirely, mother of pearl is not at the peak of its popularity. As a result, you can often find mother of pearl readily on beaches. The price depends on what kind of mother of pearl you are purchasing, the weight, and the number of imperfections.

The price will also depend on whether or not your mother of pearl has been bleached. Remember that nacre comes as the iridescent, multi-colored sheen of mother of pearl. It is often bleached to a whiter or cream color to mimic the desired pearl when harvested. Mother of pearl, however, has its own natural beauty that people appreciate prior to any modifications.

How To Clean Mother of Pearl

This biomineral only has a 3.5 on Moh’s scale of mineral hardness. The scale generally runs from one being the least hard with talc and ten being the hardest with diamond. Some substances and minerals fall between the category ratings, however. The mother of pearl is classified alongside platinum and is harder than copper, silver, and gold but less tensile than steel or opal, another iridescent mineral.

Knowing mother of pearl’s hardness informs jewelers and jewelry owners how to clean it properly without doing damage. Due to its nature as a biomineral, it is easily scratched and challenging to repair. Seeking professional guidance and expert cleaning services when you are ready to spruce up your mother of pearl will help prolong its beauty.

There are several different recommendations on how to clean mother of pearl. The advice ranges from professional jewelers to mother of pearl harvesters to families who have processed mother of pearl for generations. One method even suggested soaking the pearl back in the original waters in which it was harvested and then scrubbing with the ocean foliage there. While that particular recommendation may not always be possible, some other valuable recommendations for cleaning mother of pearl include:

The Olive Oil Method

  • Use a microfiber cloth to dust the jewelry
  • Then dip the cloth into olive oil
  • Polish the mother of pearl with the olive oil using silk
  • Allow to dry completely
  • Return to storage away from other jewelry

The Soap Method

  • Use one drop of dish soap per one gallon of water
  • Using a scratch-free sponge, gently massage in circles
  • When you have covered the whole of the mother of pearl
  • Rinse and let dry completely
  • Return to storage away from other jewelry

The Dry Method

  • Use a satin cloth and nothing else
  • Buff mother of pearl back to shine
  • Replace in storage away from other jewelry
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AllThingsNature researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AllThingsNature researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Discussion Comments

WIMoose

I've found some shells which are solid mother of pearl in my yard in WI. They are quite pretty. Wondering if anyone knows about values. They are fresh water. I have 7 shells, several inches each. Where and how would a person sell these.

Perdido

I've seen mother of pearl buttons on Western shirts. I used to go to a country dance club every Saturday night when I was a teenager, and many people would have plaid shirts with shiny nacre buttons on them.

I love the iridescence of these buttons. At the time, I had never seen any mother of pearl jewelry, but when I came across a large mother of pearl ring, I had to have it.

The nacre is a large oval that nearly covers the portion of my finger beneath the knuckle. It has a silver band that you can barely see.

wavy58

I think it's sad that living creatures are harvested so people can make mother of pearl jewelry. I wish that they could just use the dead shells that wash up on shore and leave the living creatures alone! I don't want anything to have to die so that I can have jewelry.

seag47

@kylee07drg – Interesting! I didn't know you could find mother of pearl in freshwater lakes and rivers. I've only heard of it being harvested from the ocean.

My grandmother has a lovely mother of pearl pendant in the shape of a dove. I always admired the way it changed colors in the light as she moved around.

kylee07drg

I never had to buy mother of pearl shells to decorate my house with a nautical theme. I found plenty of them by the river and the lake where I grew up.

These big, lump brown shells that look really ugly on the surface shine with mother of pearl on the underside. I even found a few that were still hinged together, and I treated these with care.

I found that I could sand off the ugly brown exterior to reveal a pretty pink color underneath. That brown stuff had started to flake off anyway, and the pink looked much more like it belonged with the mother of pearl on the other side.

wesley91

@cary: I also have used mother of pearl cream. That might sound kind of odd since I am a man but I am a true believer. I had knee surgery several years ago which left a fairly long scar on my left knee. My wife had some of the mother of pearl cream and told me to try it. I was hesitant at first. After I had been using it for about two to three weeks, I noticed results. The redness was gone and the scar seemed to start diminishing. It really works.

cmsmith10

@cary: My mom used to tell me that mother of pearl cream was the best thing since sliced bread. When I became pregnant with my first child, she told me to use it on my stomach to prevent stretch marks. I used it every day (give or take a couple of days) and ended up with only a few stretch marks. After I had my son, I continued to use it and the majority of the stretch marks faded away. There are still a few, but the results were overwhelming!

cary

Interestingly, a number of skin creams also use mother of pearl. Supposedly, the amino acids in the mother of pearl help heal skin. I'm curious if there's any proof that it actually works.

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