Freshwater and Akoya pearls, while both genuine pearls, differ greatly in value and composition. The three main differences are the culturing process, the nucleus, and the shape.
Freshwater pearls are mantle-tissue nucleated, whereas Akoya pearls are bead-nucleated. Instead of inserting a mother-of-pearl bead and a piece of mantle tissue into the gonad of a freshwater mollusk as is the process with an Akoya oyster, only a piece of mantle-tissue is used, and this is inserted into the mantle tissue of the freshwater mollusk, not the gonad. The result is a pearl composed of solid nacre, and the mantle tissue is eventually dissolved or drilled out.
Although harvested freshwater pearls are solid nacre, and Akoya pearls may only have .5mm nacre over a bead-core, the Akoya pearls are still generally more valuable. This may be confusing to some, but when we look at the whole picture and value differentiation takes shape.
Freshwater pearls are nucleated in the mantle tissue which is on either side of the oyster. This tissue is much larger than the gonad of an Akoya oyster. Therefore the freshwater mollusk can be nucleated up to 25 times on either side, for a total of 50 nucleations. An Akoya oyster, on the other hand, can handle a maximum of 5 nucleations in its gonad, but very rarely is nucleated with more than 2 beads at a time. So upon harvest, a freshwater mollusk may produce up to 50 pearls at a time, while the Akoya oyster has a maximum production of 2.
Freshwater mollusks are also much easier to farm. The mortality rate is much lower than that of the nucleated Akoya oysters, and freshwater farms rarely deal with natural disasters such as typhoons and red tides that plague Akoya pearl farms.
Aesthetically Akoya pearls are almost always nicer than freshwater pearls as well. Akoya pearls are known for being perfectly round (very rare attribute found in freshwater pearls), and they typically have a brighter shine and higher luster.
In the last decade, however, Chinese freshwater pearl farms have increased the quality of their harvests tremendously. Today it is possible to find strands that are of comparable quality to a nice Akoya strand. Although the price is still substantially lower, they are quite valuable, and these strands, being solid nacre, will be much more durable over the course of wear.
Topearl.com, Online jewelry store: Wholesale Jewelry
Post at October 1st, 2005. |
