Freshwater pearls are cultured in mollusks, rather than oysters, in freshwater lakes and rivers throughout China and Japan. These special pearls appear in a wide variety of shapes and natural colors, and they are usually less expensive than saltwater pearls, which makes them very popular with both jewelry designers and pearl lovers. Because freshwater pearl have a solid nacre, they are also quite durable, and should resist chipping, wear, and degeneration. In size, shape and color, they exist in an amazing variety of forms
Surface Markings
A freshwater pearl jewelry free of any surface blemishes is the most valuable but is very rare. Just as our own skin is rarely completely free of little imperfections, so it is with pearls. Most gem quality pearls have small blemishes such as spots or bumps that are not easily noticed but will nevertheless lower their value. Low quality pearls will have larger flaws or even small cracks. All other things being equal, the cleaner the surface, the more valuable the pearl.
Nacre Thickness
Nacre thickness is very important to the long term quality and luster of your pearls. The thickness of the nacre determines how the light reflects off of the pearl and also determines how easy it will chip or break. A pearl with very thin nacre may chip and break very easily and its lifespan will be shorter than a pearl with thicker nacre. To have a lustrous pearl jewelry, the nacre must be thick. Any pearl that exhibits a rich luster is one that has thick nacre.
Matching
Matching refers to pairs or strands, and addresses uniformity of color, luster, shape, spotting and graduation. The more uniform and aesthetically pleasing two or more freshwater pearls look together the more time was spent matching the pearls. This time to match pearls is reflected in the cost. If colors are intentionally mixed, it refers to the attractiveness of the combination. Each pearl in a strand has been selected to be placed between its neighbors on each side, and there should be no noticeable difference between pearls that are side-by-side.No two pearls are the same, which makes this step of the process so important to the overall look of a pearl strand. It takes a very refined eye and a lot of time to properly match up one of a kind pearls to make strand. Often a skilled worker must sort through thousands of pearls in order to find enough that match perfectly and will make up a uniformly beautiful strand.