If a live clam takes pearls, it can live. That is to say, the pearl mussel is opened with a shell opener, a knife edge is cut at one side of the pearl sac, and the pearl is squeezed out of the pearl sac with a top fork, so that the pearl sac is left in the mantle, and the pearl is re-secreted by the epithelial cells of the pearl sac to form pearls. A mussel can be recycled for many times, with high resource utilization rate, labor and cost saving, short breeding cycle and high annual economic benefits.

However, pearl collection usually adopts the method of killing pearl mussels and taking pearls out of pearl bags. Such a mussel can only cultivate pearls once, and the resource utilization rate is only once. If it wants to regain pearls, it must restart a series of production activities such as mussel breeding, transplanting and breeding.

Extended data:

Main items for selecting pearls:

1. Pearl variety: Generally, pearls are divided into seawater pearls, freshwater pearls and artificial pearls. Freshwater pearls are more common and the prices are relatively moderate. The rarer the output, the higher the value. Nanyang pearls are better than Tahiti pearls, followed by China seawater pearls and China freshwater pearls.

2, smoothness: dull pearls lack aura. A-class pearls look at light, and the reflected light is particularly bright and sharp, and the surface is like a mirror. Poor grades or fake ones are bleak. At the same time, the less acne, spots, marks, pits and other defects on the surface, the better, and the smoother surface.

3. Round: The rounder the pearl, the better. The price of round pearls is several times higher than that of oval or oblate pearls.

4. Size: The bigger the pearl size, the rarer it is and the more valuable it is. Generally, pearls below 6MM do not belong to the category of gem-grade pearls. 7-9MM pearls are common, and 10MM pearls are very rare. There are only Nanyang pearls and black pearls above11mm.

Baidu Encyclopedia-Pearl