Freshwater pearls, the gems of inland waterways, are begotten of irritation. Pearls form from the secretions a freshwater mollusk exudes when an irritant enters its interior domain.
This answers one of the most frequently asked questions about pearls. Freshwater pearl production, however, is not that simple.
Something as small as a grain of sand is irritating enough to make a mollusk produce a pearl. But that kind of natural occurrence is rare compared to the purposeful seeding of mollusks with beads to produce pearls.
Whether the irritant got in there accidentally or whether a person put it in there on purpose, the mollusk protects itself by coating the offending irritant with a smoothing saliva called nacre. Layers upon layers of nacre build up and one day, voila, you’ve got a pearl.
The specific techniques for cultivating freshwater pearls remain a mystery among the many trade secrets of the pearl farm producers. Pearl production in China is the largest in the world.
Generally speaking, two cultivation methods are known: bead nucleated and non-bead nucleated. Whatever the cultivation method, all freshwater pearls are made by mollusks. All freshwater pearls, whether nucleated with seed beads or not, are cultured pearls. Yes, freshwater pearls are cultured pearls.
Most freshwater pearl production is not bead-nucleated. Instead, a piece of fleshy mantle from a donor mollusk is inserted into the producing mussel. The secretions seek to surround the still irritating substance and continues anywhere from 18 months to 6 years. The result is a pearl of a size proportional to the cultivating period.
Such non-bead-nucleated pearls are solid pearl nacre on the inside. The longer the period, the larger is the pearl … or pearls. A freshwater mussel can be nucleated to produce 20 or more pearls per cultivation period. And that’s why freshwater pearls are more abundant, hence less expensive, than their saltwater cousins, which produce but one pearl at a time.
Bead nucleation in many shapes
Bead-nucleated freshwater pearls are produced by the technique implied in the term. A bead is inserted into the mollusk serving as the nucleus around which layers of nacre build up. The bead is made of mother-of-pearl or similar shell-like substance, and it’s usually spherical of one size or another.
It was found that the nucleating bead could be any shape and still irritate the mollusk enough to nacre it over. This gave rise to the production of freshwater pearls in the myriad shapes we see today, including Xs, crosses, needles, stars, triangles, squares, popcorn, bi-lobes, petals, coins, and near-rounds such as ovals, potatoes, baroque, oblongs, cones, and teardrops, among others.
Current day freshwater pearls are bound only by the imaginative shape of the nucleating bead and the creative people who carved the bead. Pearl farm production methods then prompted a clam to coat it with its organic luster.
Whatever its color, size, or shape, know that freshwater pearls are made by mollusks and not by men or machines.