Pearls have been known for centuries as objects of beauty, adornment, and purity—thanks to their rarity. Pearls are formed when a mollusk produces layers of nacre (or mother of pearl) to neutralize a microscopic object causing irritation within its mantle folds. Pearls are available in pieces of jewelry such as necklaces or used as adornment on garments. Although typically round and smooth, pearls are available in a number of variations, based on their composition and how they are produced.
The rarest and most highly valued type of pearls are natural pearls, which occur spontaneously in the wild. Natural pearls are composed of calcium carbonate and aragonite. When the irritant, usually a parasite, irritates the mollusk within its shell, the invertebrate animal creates a pearl sac out of external mantle tissue cells. Following the creation of the pearl sac is the secretion of nacre from the mantle tissue shells, which contains the calcium carbonate. This type of substance forms the pearl’s brown central section. Once the brown pebble is formed, the mollusk produces tabular aragonite for the covering, which consists of a yellowish-to-white outer zone. The nacre secretion continues over the next couple of years, thus increasing the size of the pearl over time.
Although natural pearls were once plentiful, particularly in the Persian Gulf, rapid harvesting over time has rendered them exceedingly rare. This factor—coupled with their unparalleled smoothness, roundness, and size—makes natural pearls the most expensive pearls in the world.
Cultured pearls constitute the majority of pearls created and sold today. They are grown in pearl farms, where people raise mollusks to a stage where technicians can insert a mother-of-pearl bead nucleus necessary for pearl creation. However, mother-of-pearl bead nuclei do not automatically guarantee pearl production. And even when a mollusk does produce a pearl, it is not usually as big, smooth, or round as a natural pearl. Usually, thousands of cultured pearls have to be sorted out to produce just one single 16-inch strand of perfectly matched beads.
There are two types of cultured pearls: freshwater pearls and saltwater pearls. Freshwater cultured pearls are produced in lakes, rivers, and ponds. Saltwater cultured pearls are produced in saline water, particularly in the sea. The most common trade name for cultured pearls is Akoya, which is from Japan. However, there are the South Sea and Black Tahitian brand, particularly for saltwater pearls. China is the major producer of freshwater cultured pearls; Japan is also prominent in the making of cultured pearls.
At the bottom of the totem pool are imitation pearls. As the term indicates, they are produced to look like pearls. Some are simply made of mother-of-pearl, conch, or coral shell. Others are made from glass, with a solution rubbed on the surface to form its coating. Ultimately, though, imitation pearls lack the smoothness and weight of natural or cultured pearls. Also, their luster does not last; imitation pearls tend to dim within a certain number of years. However, it can be hard to distinguish between an imitation pearl and the other types, so it is always important to consult a top jeweler to establish exactly what kind of pearl you have.
This article was written by Maya Goodwin, a fashion student who hopes to help you understand fashion better. She writes this on behalf of Saint Christine, your number one choice when looking for exquisite earrings and jewelry. Check out their website today and see how they can help you get what you need!