PEARL, a composite of
Aragonite and conchiolin

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PEARL is often considered a gemstone, although it is not a mineral. Rather, pearl is a composite of the mineral Aragonite (Calcium Carbonate) and the organic compound conchiolin (a protein). The combination is called nacre, or mother-of-pearl. In some cases, there is an admixture of the mineral calcite (another mineral composed of Calcium Carbonate). In pearl oysters and freshwater pearl mussels, nacre forms the inner lining of the shell. In most other molluscs the shell has an appearance more like porcelain, and lacks the luster and iridescence of mother-of-pearl.

A pearl is formed inside these molluscs when minute hexagonal crystals of aragonite and conchiolin (as a binder) are deposited over an irritant. As a composite, it is tougher than the aragonite from which it's formed, and the layered nature of the structure contributes to the luster of the pearl.

An ideal pearl is spherical, but other shapes are common. A pearl may even become cemented against the inner wall of the shell, and eventually become a blister pearl.

Most pearls are "cultured", meaning the oysters (or mussels) have been opened and a "seed" inserted into the flesh of the oyster. The oyster then secretes nacre over the seed, eventually covering it with mother-of-pearl and a pearl is formed. Note that a natural pearl of significant size takes many years to form, as only a fraction of a millimeter of nacre is deposited each year. But for a cultured pearl, a bead is inserted as a seed (typically composed of shell), and the oyster may be harvested (and the pearl removed) in as little as six months, although for higher quality pearls (a thicker layer of mother-of-pearl) the harvest may not be done for several years. Different species have different secretion rates of nacre, so the minimum time varies widely.

At one time, pearls were very rare and expensive, because more than a thousand oysters might be harvested to find a single pearl, and that one may have been small or misshapen. However, raising oysters or freshwater pearl mussels is relatively easy, and the process of inserting the "seeds" has been perfected, such that cultured pearls are now harvested by the ton. Still, only a fraction of the harvest will be of high-quality pearls.

Note that imitation pearls are common. These may be made of ceramics, plastics, or other materials. The simplest test (which is not, unfortunately, infallible) is the "tooth" test. Rub the pearl against the front of your tooth. If it feels smooth, it is a fake pearl. If it feels slightly gritty, it may be genuine (or a really well-made fake). There is no easy test for natural versus cultured pearls, other than to break it or slice it to see if the interior is all concentric layers (as in a natural pearl) or if the center (the bulk of the pearl) is ordinary shell material without layering.

Pearl is a Birthstone for June, and for the astrological signs of Scorpio and Cancer. It is the traditional gift for a 30th anniversary (reflecting its historical high value), although in the modern lists Pearls are to be given for the twelfth anniversary. Pearls are associated with the values of modesty, purity, beauty, and happiness.


Amethyst Galleries sells natural mineral specimens, including precious metals and gemstones, but not (at present) Pearls. For Pearls or Pearl Jewelry, please visit our affiliates.


Pearl Jewelry - Hover over an item for more information
Sphere White Cultured Pearl 14K White Gold Ring with Citrine - Pearl Trillion Ring
A stunning pearl and two 6mm, trillion-cut accent stones create a unique take on a classic designs, carefully handcrafted in your choice of gems and metals.Only $690.00 at Gemvara
no photoSphere White Cultured Pearl 14K White Gold Ring with Citrine - Pearl Trillion Ring
$690.00
Gemvara
Moonstone and Cultured Pearl Earrings in Sterling Silver
These moonstone and cultured pearl earrings go together and glow together. Featuring oval moonstones atop 14mm cultured freshwater pearls. Clip/post, sterling silver earrings. Pearl birthstones are the perfect gift for June birthdays.Only $125.00 at Ross-Simons
no photoMoonstone and Cultured Pearl Earrings in Sterling Silver
$125.00
Ross-Simons
Sphere Peach Cultured Pearl 18K Yellow Gold Ring with Citrine & Blue Topaz - Flowering Pearl Ring
A round lustrous cultured pearl encircled by 10 brilliant pave-set gems. Symbolizing integrity, personal transformation and individuality, pearls are believed to lift a woman's spirits and make her feel beautiful and confident.Only $795.00 at Gemvara
no photoSphere Peach Cultured Pearl 18K Yellow Gold Ring with Citrine & Blue Topaz - Flowering Pearl Ring
$795.00
Gemvara
Sphere White Cultured Pearl 18K Yellow Gold Ring with Peridot - Pearl Trillion Ring
A stunning pearl and two 6mm, trillion-cut accent stones create a unique take on a classic designs, carefully handcrafted in your choice of gems and metals.Only $915.00 at Gemvara
no photoSphere White Cultured Pearl 18K Yellow Gold Ring with Peridot - Pearl Trillion Ring
$915.00
Gemvara
Black & White Cultured Freshwater Pearl Button Bypass Ring, Womens
Black and white cultured freshwater pearls come together in the most classic of color combinations for a timeless look that works with any style, any time. Metal: Rhodium-plated sterling silverPearl Type: Dyed and genuine cultured freshwater...Only $112.49 at jcpenney
no photoBlack & White Cultured Freshwater Pearl Button Bypass Ring, Womens
$112.49
jcpenney
Sphere Peach Cultured Pearl 14K Rose Gold Ring with Tanzanite & Pink Sapphire - Flowering Pearl Ring
A round lustrous cultured pearl encircled by 10 brilliant pave-set gems. Symbolizing integrity, personal transformation and individuality, pearls are believed to lift a woman's spirits and make her feel beautiful and confident.Only $685.00 at Gemvara
no photoSphere Peach Cultured Pearl 14K Rose Gold Ring with Tanzanite & Pink Sapphire - Flowering Pearl Ring
$685.00
Gemvara
15mm Cultured Mabe Pearl Ring in Sterling Silver
This 15mm cultured mabe pearl ring is distinctly designed with Balinese styling influences to create a unique and contemporary look. A sure conversation piece. Sterling silver ring. Pearl birthstones are the perfect gift for June birthdays.Only $67.50 at Ross-Simons
no photo15mm Cultured Mabe Pearl Ring in Sterling Silver
$67.50
Ross-Simons
Sphere White Cultured Pearl 14K Rose Gold Ring with Diamond - Flowering Pearl Ring
A round lustrous cultured pearl encircled by 10 brilliant pave-set gems. Symbolizing integrity, personal transformation and individuality, pearls are believed to lift a woman's spirits and make her feel beautiful and confident.Only $1,000.00 at Gemvara
no photoSphere White Cultured Pearl 14K Rose Gold Ring with Diamond - Flowering Pearl Ring
$1,000.00
Gemvara
Cultured Freshwater Pearl & White Sapphire Ring, Womens
Ultra-feminine, this cultured freshwater pearl ring sparkles with lab-created white sapphires. Metal: Sterling silverMetal Color: WhitePearl Type: Cultured freshwater pearlPearl Color: WhitePearl Size: 7.5-8mmStones: .50 ctw. lab-created white...Only $124.99 at jcpenney
no photoCultured Freshwater Pearl & White Sapphire Ring, Womens
$124.99
jcpenney
8-8.5mm Cultured Pearl Oval Drop Earrings in 14kt Yellow Gold
A delightfully simple classic! These earrings drop 8-8.5mm cultured freshwater pearl ovals from richly polished leverbacks. 14kt yellow gold earrings. Pearl birthstones are the perfect gift for June birthdays.Only $71.25 at Ross-Simons
no photo8-8.5mm Cultured Pearl Oval Drop Earrings in 14kt Yellow Gold
$71.25
Ross-Simons
Cultured Freshwater Pearl Necklace, Womens
The beauty and simplicity of the pearl is showcased here, as smaller pearls lead to one beautiful dangling pearl. Metal: 10K gold Metal Color: Yellow Stone: Oval and round freshwater pearls and diamond accent Length: 17in Diamond accent: the look of...Only $249.99 at jcpenney
no photoCultured Freshwater Pearl Necklace, Womens
$249.99
jcpenney
Cultured Freshwater Pearl Ring Sterling Silver, White, Womens
A lovely freshwater pearl makes a soft and subtle style statement on this pretty sterling silver ring. Metal: Sterling silverStones: 6mm freshwater pearlJewelry photos are enlarged to show detail.Only $62.49 at jcpenney
no photoCultured Freshwater Pearl Ring Sterling Silver, White, Womens
$62.49
jcpenney
Sphere Lavender Cultured Pearl 14K Yellow Gold Ring - Pearl Solitaire Ring
This modern and sophisticated ring has a single pearl as the center stone. Carefully handcrafted in your choice of pearls and metals.Only $750.00 at Gemvara
no photoSphere Lavender Cultured Pearl 14K Yellow Gold Ring - Pearl Solitaire Ring
$750.00
Gemvara
Sphere Peach Cultured Pearl 18K Yellow Gold Ring with Black Diamond & Red Garnet - Flowering Pearl Ring
A round lustrous cultured pearl encircled by 10 brilliant pave-set gems. Symbolizing integrity, personal transformation and individuality, pearls are believed to lift a woman's spirits and make her feel beautiful and confident.Only $870.00 at Gemvara
no photoSphere Peach Cultured Pearl 18K Yellow Gold Ring with Black Diamond & Red Garnet - Flowering Pearl Ring
$870.00
Gemvara
Sphere Tahitian Cultured Pearl Sterling Silver Ring with Black Onyx - Pearl Trillion Ring
A stunning pearl and two 6mm, trillion-cut accent stones create a unique take on a classic designs, carefully handcrafted in your choice of gems and metals.Only $405.00 at Gemvara
no photoSphere Tahitian Cultured Pearl Sterling Silver Ring with Black Onyx - Pearl Trillion Ring
$405.00
Gemvara
 


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