Nacre

Nacre, also known as mother-of-pearl, is an organic–inorganic composite material made by some molluscs. It forms the inner layer of their shells and is the main component of pearls. Nacre is known for being strong, flexible, and having a beautiful iridescent shine that changes color depending on the light.

You can find nacre in many ancient kinds of bivalves, gastropods, and cephalopods. While most mollusc shells have a different kind of inner layer that gives a simple shine, nacre creates that wonderful, colorful sparkle. The inside of pearl oyster and freshwater pearl mussel shells, as well as the outer layer of cultured pearls, are all made of nacre. Other sea creatures like certain marine snails, such as the Haliotidae, Trochidae, and Turbinidae, also produce this amazing material.

Physical characteristics

Nacre, also known as mother-of-pearl, is made of tiny hexagonal plates of aragonite, a form of calcium carbonate, arranged in layers. These plates are very thin and wide, and they create a beautiful iridescent appearance because they interact with light in different ways depending on the viewing angle.

The combination of these hard mineral plates and thin layers of elastic organic material makes nacre very strong and tough. It can resist breaking and bending because the layers can slide and absorb impacts, much like bricks held together with mortar. This structure helps protect the shells of molluscs from damage and parasites.

Commercial sources

The main commercial sources of mother-of-pearl come from the pearl oyster, freshwater pearl mussels, and the abalone. These materials have been valued for their beauty and strength, especially in the late 1800s.

In the 1900s, shells from the great green turban snail Turbo marmoratus and the large top snail, Tectus niloticus, were widely used for making pearl buttons. The trade of mother-of-pearl is regulated by the Convention on International Trade in Endangered Species of Wild Fauna and Flora, which is signed by over 170 countries to protect these valuable resources.

Uses

Mother-of-pearl, also called nacre, is used in many beautiful and practical ways. In architecture, thin pieces of nacre are cut into shapes, stuck to tiles or marble, and then polished to make shiny, colorful wall coverings and floor tiles. It can also be glued to fiberglass to make light, large sheets for many building uses.

People also love using mother-of-pearl to make jewelry like earrings, rings, and bracelets because it shines and changes color in the light. It is taken from the inner layer of mollusk shells, such as oysters and abalones. Nacre is also used to decorate musical instruments. You can find it on the keys of accordions, guitars, and even violins, adding a touch of sparkle to these instruments. It has been used for centuries in art and everyday objects, such as buttons and special spoons for serving caviar.

Manufactured nacre

In 2012, scientists made a material similar to nacre in a lab by copying how it grows in nature. Two years later, in 2014, they used lasers to create a special kind of nacre-like pattern in glass. This made the glass much stronger—about 200 times tougher than normal glass—because the tiny patterns helped absorb impacts and prevent the glass from breaking.