Freshwater vs Saltwater (Akoya)
Speaking of freshwater pearls, a category of inferior pearls of small size and irregular shape may come into mind.
This may have been the case ten years ago.
For many years, China's freshwater pearl farms only produced low quality "rice" pearls, whereas seawater pearls were more spherical and of better quality. Recent years have seen ongoing improvements in the cultivation and processing techniques of Chinese freshwater pearls. From the 1990s, China surprised the market with products that are revolutionizing pearling. Freshwater pearls are gradually becoming a strong competitor of their seawater counterparts. The great value of freshwater pearls over seawater pearls lies in the following 7 aspects:
Thickness of nacre coating
Cultured seawater pearls start with a round-shell nucleus, which is introduced to the oyster by man. The oyster, over time, secretes calcium (nacre), which covers the nucleus. Generally, in all varieties of seawater pearls, the nacre coating of Japanese Akoya pearls is the thinnest -- about a half millimeter thick, the second thinnest nacre coating is that of Tahitian pearls-about 2 to 3 millimeters thick. South Sea pearls develop the thickest-from 2 to 6 millimeters.In contrast to seawater cultured pearls, freshwater pearls are all pearl -- this is the biggest selling point to freshwater pearls. Due to the fact that there is no nucleus inserted in freshwater pearls, our pearls are all nacre, unlike their seawater counterparts. Accordingly, the risk of thin nacre of pearl wearing off over time is not an issue with the freshwater pearl.
In all seawater pearl varieties, only South Sea pearls can have a nacre coating as thick as that of freshwater pearls. But, to have the same thick nacre coating of a 10mm freshwater pearl (the coating of which is therefore 5mm thick) a South Sea pearl should be 18mm in size. You will have to spend a small fortune to have it. On the other hand, it only costs a small fraction of that money to buy a 10mm, top quality freshwater pearl.
Colors and Shapes
Freshwater pearls have a special allure since they are offered in a wide range of colors-much more variety than seawater pearls. Thanks to the content of a very small quantity of metal elements, such as copper, silver, natrium and zinc, the colors of freshwater pearls are very diverse, many of them unseen in sea waterpearls. Some are so rare and unusual that they are just beyond imagination and expression. These pearls are no doubt very attractive to jewelry designers.
Freshwater pearls can be found in all the shapes possible: all beautiful in their own right -- round, drop, rice, button, oval, semi-round, circle or ringed, baroque and semi-baroque. Some shapes are even very peculiar. Because of its popularity, the round shape is usually the most expensive, but as always, personal preference dictates the shape each customer will find most beautiful. In fact, baroque shape, like the variety of colors, offers jewellers most scope, although farmers aim for smooth round cultured pearls.
Longer cultivation period
Generally, South Sea pearls and Tahitian pearls take 2 to 3 years to form. Japanese Akoya pearls take a shorter period, less than 2 years. The standard cultivation period for Chinese freshwater pearls in the 1980s was between 1.5 to 2 years. The relatively short time resulted in small size and low quality. But in the past 10 years, Chinese pearl farms changed their way of cultivating pearls and let their implanted mussels stay in the water for a much longer time. Nowadays Chinese freshwater pearls take from at 3 years to as long as 5 to 6 years before they are ready for harvest. Such a long cultivation period leads to freshwater pearls that are much bigger in size and much higher in quality; meanwhile, it is a rigorous test to Chinese pearl farmers' patience and financial strength.
Due to farming technique improvements and longer cultivation periods, the size of Chinese freshwater pearls is becoming bigger and bigger. Sizes below 6mm, now regarded as small, are actually dying out in the market. Large freshwater pearls in the range of 9 to 16 mm are comparable to South Sea pearls in size yet more competitive in price. We therefore believe that this category of pearls shall continue to remain one of the driving forces in the markets as they have done before.
The shapes, surface and luster of the new Chinese production have already surpassed the original Biwa quality. As testimony to China's achievement, good freshwater pearls are now round enough, clean and lustrous enough to pass as Japanese Akoya and South Sea pearls.
Rarity of freshwater pearls
Each year, millions of mussels are implanted. But only a very small proportion live to bear fine quality cultured pearls. On average, about fifty percent of the harvests are not marketable pearls. They are too imperfect or too flawed to be used as jewels. Less than one percent of those marketable are of perfect shape, luster and smoothness.
As for those high quality and large size freshwater pearls, they are of no doubt more rare. They are extremely rare basically for three important reasons: one is that freshwater pearls start with a small piece of mantle tissue, not with a much bigger shell nucleus as seawater pearls do, therefore it takes exceptionally longer to cultivate large size freshwater pearls. For example, at least 5 years are needed to make a 10 mm freshwater pearl. Many farmers who are not financially strong enough just can't wait so long. The second reason is that even if you placed an implanted mussel in the water for a long enough time, you may not anticipate whether its production will be of large size. For some strange and unknown reasons, some pearls just refuse to continue growing after several years' stay in the mussel. Therefore, large sizes always account for a small part of the harvest no matter how long the cultivation period is. The third reason still rests in the pearl's long cultivation period -- any pearl is more likely to become flawed the longer it is left in the mussel, and so a perfect, large size freshwater pearl is truly a rare event, blessed by Mother Nature.
According to the market actuality, we can safely say that perfect large size freshwater pearls, such as 10 mm freshwater pearls are much more rare than any same size seawater pearls of the same quality.
Most competitive price
China has improved its cultivation methods and processing techniques. These two factors, along with the low labor costs and the vast number of unpolluted lakes in China, have created a pearl that is much less expensive, yet its upgraded quality rivals that of the more expensive seawater pearls. These highly affordable freshwater pearls provide excellent value, variety and long lasting beauty. Indeed, pearls from freshwater mussels lie at the center of the liveliest activity in pearling today.
It is not our nature to bury our heads, like ostriches. We clearly see the fact that the image of freshwater pearls is still somewhat lower than that of other categories of pearls. Low quality does occur to seawater pearls. But the inflow to the market of these lower quality pearls is strictly and successfully controlled by the seawater pearl industry, preventing them from destroying the perfect image of the seawater pearl. Freshwater pearls, on the other hand, have no such control yet. Medium and low quality products flush over the market, deteriorating the freshwater pearl's image. But, to conclude that seawater pearls are superior to freshwater pearls simply by comparing the best quality seawater pearls on the market with the flood of low quality freshwater pearls is not fair play. After all, it is each individual pearl's merits that determine the value more than the source of the pearl. As we have pointed out many times, freshwater pearls are not just "Rice Krispies”, there are also top quality pearls of high luster and perfectly round shape. It's a common wish among members of the Chinese freshwater pearl industry that the image of freshwater pearls is improved by educating customers and promoting top-quality pearls.