Japan is widely regarded as the origin of the " manmade" pearls, but by the time Kokichi Mikimsto sparked the Japanese cultured revolution in the early 1900's, Chinese had already been inserting Buddha images into mollusks to create nacre-covered amulets for seven hundred years.
However, despite the long history, freshwater farming technologies in China remained basically the same in the past century, except for the changes made in the 80's, where mussels for pearl cultivation were artificially propagated. China became the indisputable center of world freshwater pearl industry not because of the techniques but mainly because of low labor cost and abundant pristine and unpolluted water areas. However, over the years, China has seen a change in the techniques and technologies in freshwater farming. In the past five years, considerable improvements were made, new methods were employed, thereby making Chinese big farms capable of supplying large size (9mm to 16mm) and top quality (as good as that of the best seawater pearls) freshwater pearls.

Innovative Farming Techniques
Selecting water area
Implanted mussels are not irresponsibly placed in whatever lakes or ponds outside a farmer's front yard as they were several years ago. Big companies like Grace Pearl has experienced personnel scouting around Eastern China for suitable water areas. Clean, unpolluted water doesn't necessarily produce pearls of high quality. Our company now routinely sends water samples to the China Science Academy for quality analyses on factors of nutrition, bacteria, oxygen content, PH value, plankton, etc. We go wherever desirable water locates. That is why we have farms scattered in all six provinces of the Chinese pearl producing areas.

Using Hyriopsis Cumingii
In the 1980s and early 1990s, most farms used Cristaria Plicata because it produces quickly. Pearls from this species are oblong or irregular shaped, of poor quality. Now we are using a new species - Hyriopsis Cumingii. This species usually yields the best quality round pearls with high luster and big size, but takes a long time to grow.

Buying implanted mussels
While implanting mussels themselves, big farms also buy from small farms already implanted mussels that have been grown in water for 1 to 2 years. Though it costs much more, the risks are decreased since the mortality rate is highest during the first year after implanting. It is also a quality-control method simply because you won't spend money on those implanted mussels if you find the baby pearls inside are of low quality and irregular shape. As for the small farms, they are willing to sell their young mussels, as long as it's profitable.

Various feedstuffs
Implanted mussels used not to be taken care of after being placed in whatever nutritious or infertile water. They fed and grew only by the nutrient contained in lake water. As the years progress so does the treatment. Implanted mussels, especially those in big farms, are given the utmost care, not just left to Mother Nature. Recently they have been enjoying various feedstuffs ranging from carbamide, soybean milk to fermented organic fertilizer such as bean cake and chicken manure, even compound manure developed specifically for pearl mussels. These contented mussels then present people with their lovely gift -- high quality and big size freshwater pearls.

Disease prevention and cure
Implanted mussels are susceptible to bacteria, virus, plankton and/or some other microorganisms unknown to people. Some ferocious freshwater fishes eat mussel's protruded meat while they are breathing. When an unfortunate mussel plague happened in the past, there was no way out. The only thing farmers could do was curse fate and watch their mussels die away. Things have somewhat improved nowadays. With the help from scientists, special medicaments have been invented and to some extent diseases may be controlled, making it more possible to cultivate mussels for longer periods. But we are not too optimistic yet, the plague still remains the biggest problems that the industry has to face.

Cultivation period
In former times implanted mussels were cultivated only for a period of 1.5 to 2 years before harvesting. This short time of cultivation resulted in small size (no larger than 7 - 8 mm.) and often low quality. Inferior freshwater pearls rushed over the market, destroying their own image. That explains why many people still rank freshwater pearls in the lower tier of the whole pearl family. However, in the past decade, some farms were getting financially strong enough and extended the cultivation period to as long as 4 to 5 years, or even longer. Now we are able to supply to the market top quality freshwater pearls of big size (9mm to 16mm). If a 10mm, best quality freshwater pearl is put together with a same size seawater pearl such as a Japanese Akoya pearl, believe me, you won't tell any difference between them.

Common Farming Practices
Water condition
Water condition is the key to mussel growth with an ideal temperature between 18 and 25 degree Celsius. The water should be peaceful, well circulated, contain plenty of nutrients, have no pollution, and a depth of 2 to 2.5 meters (definitely not more than 4 m). If the water is too shallow, the temperature will shift too rapidly and the mussels will die. The flow speed should be about 6 meters per minute. Ideal acid - alkali concentration is 7 to 8 ph. If it's too acidic, the pearls will be small; too much alkali and the pearls come out yellowish. Water visibility should be 25 to 40 cm. The farms should not be in polluted areas.

Pearl farming
Generally, farms in the Eastern region of China plant between March and May and September and October since in summer the water temperature is too high for just-operated host mussels to survive, while in winter it's too cold for technicians to carry through tricky implant work with their numb fingers. Farms usually harvest between October and February, because during the fall and winter seasons mussels produce nacre layers more slowly, resulting in a smoother surface and higher luster.

Stages in farming

Selecting mussels
The mussels are divided into two groups: those providing implantable tissue and mussels to be implanted. The selected mussels soak in a basin for a few days, are cleaned and put in a wooden basin with water level slightly lower than the mussels so they can breathe.

Preparing Tissue Implants
Tissue is cut from the mussels into one or two long pieces on each side of the shell 0.4 to 0.5 cm wide and then cut into rectangles of 4X5 mm. The whole process from shell opening to tissue preparation and implanting should take less than 15 minutes.

Implanting
The mussel is opened only 1 to 1.2 cm wide to avoid injury. A piece of tissue is placed in the triangular scalpel slit and shaped into a round using a needle. It is crucial that the tissue not make contact with the shell. The triangular slit runs from top to bottom 1 to 1.2 cm wide and 0.6 cm deep. The implanted tissues are placed 1 to 1.5 cm apart with three rows in each shell 1 cm apart. The number of tissues implanted depends on the size and health of a given mussel. For example, a 10 to 15 cm long mussel could be implanted with 30 to 40 pieces of tissue, with 15 to 20 pieces on each side.

Suspended in the water
Three or four mussels are placed in a bamboo basket or nylon net and hung at 0.5 to 1 meter intervals from a long thick nylon rope above, which is tied to two bamboo poles at its two ends respectively. The rope is floated by buoys.

Tending mussels
The mussels are taken good care of while suspended in the water. Technicians check water temperatures and feeding conditions, moving the mussels up or down as appropriate. Periodically, the mussels are lifted from the water for cleaning and health treatments. Aquatic weed, barnacles and other organisms that might interfere with their feeding are removed from the mussel's shell. It is a lot of work, much of it repetitious and labor intensive. Tending the mussels is a continuous process aimed at smoothly developing the pearls to minimize blemishes. The painstaking work can last four to five years long.

Harvesting and Processing
Harvested pearls are cleaned immediately in freshwater. They are scrubbed, and then washed in warm water followed by several more soap and fresh water washings. They are then dried and sent for sorting, drilling and matching.