From the most expensive piece of jewelry in history to one of the most versatile beads in your basket... pearls always fascinate!
Throughout much of recorded history, a natural pearl necklace made up of matching spheres was a treasure of almost incomparable value -- in fact, the most expensive jewelry in the world! Before the creation of cultured pearls in the early 20th century, pearls of any sort were so rare that they were reserved for the noble and very rich. To prove the great wealth of Egypt, it is said that Cleopatra won a contest with Marc Antony to give the most expensive dinner in history by crushing and adding to a glass of wine a single large pearl worth about 30 million sesterces (or about $4,700,000)!
However, around 1907, several Japanese men working simultaneously discovered that they could entice oysters to create pearls. As the process has been refined, these cultured pearls have become virtually indistinguishable from natural pearls, making the most valuable gem in the world become the beauty that we can use in our beading designs today for just pennies apiece!
How Pearls Are Formed
Natural pearls are formed when an irritant or parasite enters an oyster or mussel and cannot be expelled. To reduce irritation, the mollusk uses its mantle to coat the intruder with the same secretion it uses to build its own shell, nacre (also called mother-of-pearl). Continuous layers of nacre grow like an onion skin around the irritant, until the pearl is harvested or it becomes too large for its host. Pearls vary in shape, depending on the shape of the foreign body being coated.
However, mollusks are normally very good at expelling these foreign bodies before the pearl-forming process begins -- so naturally-occurring pearls are found in perhaps one of every 10,000 bivalves. On the other hand, with culturing techniques, every one of those 10,000 creatures could create a pearl -- or more than one! Culturing is a process that is simple in concept but requires great skill to perform. In essence, an irritant (commonly a piece of mother-of-pearl from a Mississippi river mussel) and a small piece of mantle tissue (a "graft") are inserted by a specialized technician. Great care must be taken, or the oyster or mussel may be damaged in the process or even die.
After a short rest, the mollusk begins to coat the nacre "seed" just as it would a natural irritant. Layer upon layer grow, until the pearl is large enough to be harvested. Cultured pearls are composed entirely of nacre, just as natural pearls are, so they exhibit the same structure, color, and gorgeous luster as their more expensive counterparts. Additionally, a wide variety of seed shapes may be used, to create interesting new pearl shapes, from the now-familiar rice and potato pearls to the more unusual baroque, matchstick, drop, and cross shapes.
Nacre’s luster and fallen moonbeams: Pearls’ iridescence explained
The crystalline structure of nacre (which is a combination of the mineral aragonite and the protein conchiolin) reflects light in a unique way, giving pearls their high luster. Light rays reflect not only off the surface of the pearl, but also off the concentric inner layers of nacre, which act like tiny prisms and create iridescence within the tiny sphere. This distinctive glow fostered the belief, long ago, that pearls were moonbeams which fell into the ocean and were eaten by oysters. Consequently, they have been believed magical, and symbolized the moon, purity, spirituality, and virtue for centuries.
Caring for your Pearls
Avoid contact with hair spray and perfume. Wipe with a soft, damp cloth and store them in a soft cloth. Wear them often -- your natural body oils help to keep them from drying out.