- Origin of the name : From the etymology of the Arabic word "naqqarah", deriving on the word "nacre".
- Chemical composition : Calcium carbonate and organic compounds, CaCO3.
- Hardness : Between 3,5 and 4
- Crystal System : Bivalve molluscs
- Deposits : Akoya, Australia, Tahiti, Mabe, Keshi, in fresh water
- Colors : Silvery white, Cream, Pale bluish gray, Purplish gray to black, Light pink.
Mother-of-pearl stone has been used by most peoples since prehistoric times, since the end of the Paleolithic. Its iridescent reflections aroused fascination among the First Peoples, who attributed it a symbolic link with the land and the sea. Its uses were numerous:
- Pearly shells were mainly used to make jewelry ornaments; the shells were pierced, sometimes cut and threaded.
- The shells were used to decorate art objects or religious objects, using the iridescent reflections of the pearly part of the shell.
- The shells were used as a currency of exchange. Examples of this commercial use are numerous in the Indian Ocean, the Pacific Ocean, North America, Africa and the Caribbean. They could be exchanged hundreds of kilometers from their place of origin; they were all the more valuable as they were traded by peoples living far from the coasts.
- The shells were also used as tools, because of their resistance, the variety of their forms. It was easy to cut them to give them a precise and useful shape: the smallest ones could be used as spoons or bowls, while the largest ones were used as basins. Their sharp edges were ideal for shaping knives and saws.
- Shells were also widely used as wind musical instruments by drilling a few holes, especially in spiral shells.
In addition to these usual uses, some cultures used pearly shells for more specific purposes :
- The Chinese used it to make figurines of their gods.
- The Yaqui Indians of Mexico, according to the American anthropologist Carlos Castaneda, wore necklaces made of mother-of-pearl called "hopo'orosim". They had a spiritual function, as protection against the forces of evil.
- Precious jewelry and tools made of mother-of-pearl shells were found in the treasures of the Sumerian royalty of Mesopotamia.
- The first Christians adopted the shells as symbols of resurrection. Later, the scallop shell was linked to the apostle James, the object of pilgrimage to the northwest of Spain, to Santiago de Compostela. In addition, the mother-of-pearl stone, by its milky and soft color, was related to maternal love, especially the love of the Virgin Mary. This is why many rosaries used to count prayers are made of this material. Baptismal fonts, the basins used for baptism, are often made from the largest shells. The milky, white and soft aspect of the pearly part of the shell combined with the baptismal water makes it a symbol of purification.
- Native American tribes of the northeast, especially the Algonquins, used shells to weave "wampum", precious and sacred ritual objects. They were used to decorate belt ornaments, necklaces, but also as currency or gifts to seal a pact. Tubular shells were used to decorate hair.
- The Maya made dental implants with mother-of-pearl.
- The mother-of-pearl shells were very present in Hinduism. The conch is one of the eight Ashtamangala emblems of good omen in Hinduism, Buddhism, Jainism and Sikhism. The dextrogyra white shell is the trunk of heroes in Hindu epic literature. The Panchajanya conch is one of the attributes of the god Vishnu: it represents the creation of the world, of the primordial ocean.
- In Buddhism, the conch represents the voice of Buddha and his teaching.
- The aborigines of Australia used the melo melo or volute scoop, a shell provided with a large round part, to refloat their canoes.
- In Caribbean Santeria, the religion originating in Cuba, derived from the Yoruba religion, divination uses shells as a medium.
In a more contemporary way, mother-of-pearl became more in demand after Elizabeth I gave it the name "Mother of Pearl" in the 15th century, referring to the similar process of creating pearls and the pearly coating of shells, but also to maternal symbolism. It was then used to make pendants and precious art objects.
Currently, it is mainly used in jewelry and watchmaking. It is also used in the making of buttons, art objects and inlays in marquetry. In the making of jewelry, it is often associated with onyx, with which it contrasts pleasantly, onyx being of intense black uyn. In alternative medicine, particularly in reiki and aromatherapy, some treatments are carried out by the application of shells, because of their curative properties. They are also used for divination: each shell carries a specific symbolism and message.
Etymologically, the word "nacre" comes from the Arabic word "naqqarah". Organically, it constitutes the smooth lining of iridescent shine of the shells of molluscs such as oysters, abalones, mussels... It is biosynthesized by the mantle of molluscs, a shell made up of teguments and muscles that houses the other organs. This mantle secretes the shell.
It is formed by a regular juxtaposition of 0.5 µm thick layers of aragonite, welded by a 20 nm thick organic glue, a protein called conchyoline. Conchyoline represents a minimal part of the pearlescent coating (4 to 6%) while aragonite crystals account for more than 90%. When an irritating foreign element penetrates the shell, causing irritation, the molluscs also have mother-of-pearl all around to protect themselves from it; layer after layer, this protection becomes a pearl. The mollusc produces it continuously during its lifetime.
Between the layers of aragonite and conchyoline there are traces of water and various ions: it is their particular arrangement that causes iridescent reflections, creating interference with light radiation. The reflections depend on the angle of lighting and the position of the observer; the movements of the shell or the observer thus produce the characteristic iridescences.
In addition to these fascinating iridescences, the pearly coating can present a particular coloring, which varies according to the varieties of shells. This coloration comes from the carotenoids contained in conchyoline. Manufacturers have tried to reproduce its special appearance.
From the 17th century onwards, fish scale paints were marketed under the name "Essence of the Orient". More recently, the plastics industry has used lead phosphates to give a pearly appearance to buttons.
Other chemical compounds have been developed to copy the pearly iridescent reflections. PW14 is the most frequently used pearlescent pigment today; it is a bismuth oxychloride. The chemical industry created compounds of mica and metal oxides to provide pearlescent pigments of all dominant colors; this process was patented in 1963.
Other chemical processes are used: pearlescent pigments can be made by coating silica or aluminum particles with layers of varying refractive indices. This process creates the light variations that are characteristic of the pearlescent appearance. These pigments are used in cosmetics, in the automotive industry for body paint.
The pearlescent coating of shells is a biomineral; it is produced by the transformation of minerals into a rigid mineral compound from a matrix composed of conchyoline. There are about 60 types of biominerals known by researchers, but it has the particularity of presenting unique mechanical and physicochemical properties that are very different from other biominerals. One of these peculiarities is its astonishing resistance. In particular, it is quite resistant to acids and heat. It is more resistant than the shell despite its apparent fragility. It repairs itself after being pierced or damaged when the shell is alive.
These unique properties are studied in biochemistry and biomimetics; however, researchers do not know how to reproduce it. The quality and structure of mother-of-pearl vary according to the species of shellfish and the stages of their growth. It is the proteins, especially conchyoline, which structure the pearlescent mineral and which confer particular qualities to the nacreous coating of each species of shellfish. The soluble part of the conchyoline generates the aragonite crystal, while the insoluble part determines its density, size and quantity.
Several varieties of pearly shells exist :
- The mother-of-pearl of the pearl pintadines, i.e. pearl oysters. The main suppliers are the pearl farms of the South Seas. The shell of a large pintadine can weigh up to 5 kg.
- The pearly Burgau shell, from the shells of the same name. It has astonishingly bright reflections. It has been widely used to decorate fans.
- The pearly shell of Paua, the "opal of the seas" or abalone. It was used by the Maoris to decorate their wooden cult objects, very appreciated for its iridescent blue-green play of colors. The abalone owes its nickname of "sea opal" to the proximity of its reflections with those of the black opal.
Mother-of-Pearl Meaning and Properties
Mother-of-Pearl Metaphysical Properties
On a psychological level, this stone produces appeasement; it soothes anxieties, anger, tension, mood swings and all excessive emotional states. It acts as a powerful mood regulator for the wearer. It releases fears and anxieties that affect daily life; it helps to fight against a negative state of mind. It promotes more measured and thoughtful positions and a more calm and clear expression of opinions and decisions.
Its beneficial side on emotions contributes to a better understanding of oneself and others as well as a capacity to step back from daily life. It is very effective in purifying relational difficulties, especially in love: it facilitates communication and more balanced and harmonious relationships. Its use makes it more receptive to the needs of its partner. Its soothing side makes it easier to express one's feelings of love and emotions on a daily basis, to verbalize one's needs and feelings.
On a spiritual and energetic level, it is a powerful stone of intuition and open-mindedness: it stimulates imagination and creativity. It purifies the aura and thus facilitates access to the astral body. It promotes the circulation of energy. By regulating the emotions, it helps to focus the mind and access wisdom and better self-control. It is particularly beneficial to the solar plexus chakra (3rd chakra) and the frontal chakra (6th chakra).
Its slow and natural production in an aquatic environment gives it a strong vibratory power and a powerful purifying capacity: the person wearing a pearly object benefits from the energy of the water, it rebalances the energy circulation between body and mind, thus promoting health.
Mother-of-Pearl Healing Properties
The regenerative qualities of mother-of-pearl are of particular interest to medical researchers. Indeed, it has a capacity for bone regeneration that is highly sought-after in reconstructive surgery. In lithotherapy, this biomineral brings multiple benefits to the health of the wearer:
- It would be beneficial to protect and stimulate the digestive system.
- It is indicated to fight against sore throats or headaches. It stimulates the immune function, helps the body to prevent the development of foreign bodies in the body and the desire to vomit.
- It is particularly effective in the treatment of dizziness, injuries and eye disorders, improving vision.
- Just as it has an action against anxiety and emotional disturbances, it is very indicated to relieve muscular tensions, spasms, mental functions. It helps to regulate the negative effect of emotions on physical tensions.
- It is an excellent stone in the event of excess tension, which it helps to regulate.
- It is indicated in case of calcium deficiency.
- Its regenerative action is also effective in the healing of wounds. It can reinforce muscular tissues and the heart. It is also known to help treat joint disorders.