Mother-of-Pearl Gemstone Information
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About Mother-of-Pearl - History and Introduction
Mother-of-pearl is the nacreous inner shell coating of pearl-producing mollusks. These creatures have three layers to their shell; the outermost periostracum, followed by a layer of calcite and then the innermost layer of nacre (mother-of-pearl). This smooth part of the shell is produced by the mantle of the mollusk as it grows.
Natural mother-of-pearl is found all over the world and is more common than pearl. This is because the mollusks that produce pearls will always have a shell, but will very rarely contain a pearl. A mollusk will produce a pearl to protect its soft body by enclosing a parasite or foreign body in nacre. Since natural pearls are so rare, they are cultured to allow more people to acquire them, but this is not necessary with mother-of-pearl.
Mother-of-pearl has been used for thousands of years; it was used by the ancient Egyptians and Sumerians. Inlay work has also been used in East Asian and Islamic religious art. In the West, mother-of-pearl became extremely popular during the Victorian Era. The Victorians used mother-of-pearl inlay to decorate household items such as knife handles, jewelry boxes, buttons and screens. In the 1880s, the leaders of London street traders (known as Costermongers) began to decorate their hand-me-down suits with hundreds (and sometimes thousands) of mother-of-pearl buttons. These people were known as "Pearly Kings" and "Pearly Queens". Part of the philosophy of the Pearly Kings and Queens was to give to others. This community continues charity work to this day, proudly wearing their pearly suits. The USA produced and exported mother-of-pearl buttons in great quantities, until plastic offered an alternative. Mother-of-pearl inlay is still used to decorate guitars and other musical instruments.
Mother-of-pearl can typically be identified by its pearly luster and iridescence. Some mother-of-pearl, such as that from conch shells has a porcelain-like luster and a flamed iridescence, due to a different internal structure. A detailed analysis of the structure can be used to determine true mother-of-pearl, which is composed of aragonite (calcium carbonate) crystals with conchiolin.
Like pearls, mother-of-pearl comes from all over the world and can be found in saltwater and freshwater. Mother-of-pearl sources include Australia, Japan, Central America, the Persian Gulf, the Gulf of Manaar (between India and Sri Lanka), Madagascar, Burma (Myanmar), the Philippines, the South Pacific Islands, South America, China, French Polynesia, Europe, North America and Southeast Asia.
Buying Mother-of-Pearl and Determining Mother-of-Pearl Value Back to Top
Mother-of-Pearl Color
Like pearls, mother-of-pearl can be white, gray, silver, yellow, blue-green, bronze, pink, red, brown, black or banded. Arguably the most beautiful mother-of-pearl colors are produced by abalone. These have iridescent and vivid purple, blue and green colors that are highly prized. The iridescence of mother-of-pearl is known as "orient" and is thought to be caused by light interference (interaction of light that is similar in source or frequency) and dispersion (separation of light into its respective colors).
Mother-of-Pearl Clarity and Luster
Mother-of-pearl is an opaque to translucent gemstone. When in the form of a thin layer, mother-of pearl can exhibit some translucence, but thicker sections tend to be opaque. The luster of mother-of-pearl is typically pearly. The luster of mother-of-pearl is the result of both surface and internal reflection of light. Typically, a thicker layer of nacre produces a more impressive luster; this is why the most valuable pearls have sharp, bright reflections. Some mollusk species produce mother-of-pearl with a porcellaneous (porcelain-like) luster and a flame-like iridescent pattern. Such mother-of-pearl includes that of conches and melo melo shells. This is because the aragonite crystals are oriented differently to "nacreous" mother-of-pearl.
Mother-of-Pearl Cut and Shape
Mother-of-pearl tends to be used mostly as inlay, or carved into cameos and other fancy shapes, such as flowers. Cameos are sometimes placed onto a contrasting backing, to make them stand out, or are carved from mother-of-pearl that has different colored layers. Mother-of-pearl can also be seen in cabochon gemstones. These tend to have a very low dome because of the thinness of the material. Thin pieces of mother-of-pearl are also assembled into doublets. This means that they are glued to a stone backing which increases the durability of the gemstone. If a mother-of-pearl gemstone appears to have a high dome, this may indicate that it is an assembled triplet, which has a layer of transparent quartz or other material over the surface.
Mother-of-Pearl Treatment
While mother-of-pearl gemstones are found natural, some come from cultured mollusks. Sometimes mother-of-pearl gemstones are bleached to produce a uniform white color, or dyed to produce other colors. Mother-of-pearl may also be assembled into doublets. Doublets are usually a layer of mother-of-pearl that is glued onto a stone backing. This is done to stabilize the gemstone and render it more durable. Also, the backing tends to be dark, which provides a contrast to the pale mother-of-pearl and optimizes the iridescent play of color. Sometimes a layer of colorless quartz or another material is placed over the top of mother-of-pearl, which also increases the durability. If the gemstone has a backing, in addition to a top layer, this is known as a triplet. All enhancements and treatments are acceptable, as long as they are clearly stated by traders.
Chemical Formula: |
Calcium carbonate + organic substances + water |
Crystal Structure: |
Orthorhombic |
Color: |
White, gray, silver, yellow, blue-green, bronze, pink, red, brown, black, banded |
Hardness: |
2.5 to 4.5 on the Mohs scale |
Refractive Index: |
1.53 to 1.69 |
Density: |
2.60 to 2.87 |
Cleavage: |
None |
Transparency: |
Translucent to opaque |
Double Refraction or Birefringence: |
-0.156 |
Luster: |
Pearly |
Fluorescence: |
Weak, black mother-of-pearl: red to reddish; river mother-of-pearl: strong: pale-green |
Please refer to our Gemstone Glossary for details of gemology-related terms.
Mother-of-Pearl: Related or Similar Gemstones Back to Top
Mother-of-pearl belongs to the small group of organic gemstones. These include coral, amber, jet, ivory, ammolite and pearl. Mother-of-pearl is most closely related to pearl, since they both come from the same organisms; bivalve mollusks or marine gastropods.
While most people are aware of oyster and mussel pearls and mother-of-pearl, many do not realize that there are various types of mother-of-pearl and pearls which come from creatures such as conches and abalones. The gemstone products of these creatures are incredibly beautiful, with vivid, iridescent colors. Abalone mother-of-pearl is sometimes referred to as "sea opal" because of its beautiful play of color.
Mother-of-Pearl Mythology, Metaphysical and Crystal Healing Back to Top
Some of the metaphysical properties and lore associated with pearls can be attributed to mother-of-pearl. For example, mother-of-pearl is believed to encourage prosperity. Some say that mother-of-pearl offers soothing, motherly protection from negative energy and love. Due to this, mother-of-pearl is a recommended crystal healing gemstone for children. Mother-of-pearl is also thought to promote intuition and imagination.
Disclaimer: Metaphysical and Alternative Crystal Healing Powers and Properties are not to be taken as confirmed advice. Traditional, Ceremonial and Mythological Gemstone Lore is collected from various resources and does not represent the sole opinion of SETT Co., Ltd. This information is not to replace the advice of your doctor. Should you have any medical conditions, please see a licensed medical practitioner. GemSelect does not guarantee any claims or statements of healing or astrological birthstone powers and cannot be held liable under any circumstances. |
Mother-of-Pearl Gemstone and Jewelry Design Ideas Back to Top
Mother-of-pearl is ideal for inlay and carvings. This is the reason why mother-of-pearl became so popular during Victorian times, when it was used to decorate household items such as knife handles, jewelry boxes, buttons and screens. Mother-of-pearl can be used to make incredibly attractive inlaid bracelets, cameos for necklace pendants, bib and breastplate necklaces or brooches. Another recommended use for mother-of-pearl is for men's jewelry items, such as cuff links, tie tacks and signet rings. Additionally, mother-of-pearl is a material commonly seen in high-end watch dials. Mother-of-pearl can also be drilled and strung as necklaces or bracelets in modern, high or tribal style. White mother-of-pearl gemstones are ideal for bridal jewelry and hair decorations, as an alternative to pearl. Mother-of-pearl can also be set into beautiful necklace or earring pendants that catch the light and show off an array of iridescent colors. Both white and yellow precious metals are suitable for mother-of-pearl gems.
Note: Buy colored gemstones by size and not by carat weight. Colored stones vary in size-to-weight ratio. Some stones are larger and others are smaller than diamonds by weight in comparison.
Mother-of-Pearl Gemstone Jewelry Care and Cleaning Back to Top
Mother-of-pearl is rather soft, compared to other gemstones. Although mother-of-pearl does not have a high level of hardness (2.5-4.5 on the Mohs scale), it is known to be extremely tough and strong. This could be because of the structure of the nacre and its lack of cleavage. The main component of nacre is aragonite, which is somewhat brittle calcium carbonate. Brittleness is a quality that does not lend itself well to gemstones and jewelry. However, Professor Gilbert of the University of Wisconsin-Madison researched the properties of nacre and found it to be 3,000 tougher than aragonite alone.
The pearly luster and iridescence of mother-of-pearl can be dulled by perspiration, so it is advisable to gently clean mother-of-pearl gemstones with a soft cloth after being worn. When cleaning, avoid ultrasonic cleaners and heat steamers. Simply use warm water and a mild soap or detergent. Wipe gems down using a soft cloth and be sure to rinse them well to remove any soapy residue. Avoid using any harsh chemical or cleaners, such as bleach, ammonia or acid. Also avoid any prolonged exposure to heat, direct sunlight or extreme temperature fluctuations.
Always remove any mother-of-pearl jewelry before engaging in vigorous physical activities such as sports. Despite the toughness of mother-of-pearl, it can be easily scratched by other harder gems and jewelry, so it should be stored separately from other gemstones. It is best to wrap mother-of-pearl gemstones in a soft cloth or place them inside a fabric-lined jewelry box.
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