At present, there are many kinds of pearls on the market, but there are only three categories: cultured pearls, natural pearls and pearl fakes. Cultured pearls are divided into freshwater cultured pearls and seawater cultured pearls. Freshwater cultured pearls are seedless and artificially cultured in lakes, ponds and other environments with a water depth of less than 4 meters. Freshwater pearls are irregular in shape, even the first-class pearls are oval or oblate. Mariculture pearls are produced in tropical or subtropical shallow waters, and all of them are cultured by nucleate method (if you see pearl cores in seawater pearls, don't think they are plastic, but they are made of mussels). Seawater pearls are generally round in shape. Natural pearls are mostly round and granular, with tiny nuclei, which are usually invisible to the naked eye. The distinction between natural pearls and freshwater cultured pearls has always been a difficult problem, but experts can accurately distinguish them according to the nacre structure, density, fluorescence and transparency of pearls. For consumers, the simple identification method is: natural pearls have very small nuclei and are seedless to the naked eye; Mariculture beads have nuclei and bigger nuclei; Freshwater cultured pearls are seedless. Artificial cultured pearls (freshwater pearls and seawater pearls) have good transparency, translucent gel-like appearance, while natural pearls have poor transparency and dignified appearance; There are often uneven pits on the surface of cultured beads, which are naturally pearly and smooth. Pearl imitation is also called imitation pearl. There are three kinds of imitation pearls-wax-filled glass imitation pearls: hollow round ivory balls filled with paraffin. This kind of pearl has low density and light weight, which can be distinguished by hand. Using a needle to detect that the inside of the bead is soft. Its appearance is smooth and cannot be carved with a needle; Solid glass imitation beads: white solid glass balls are soaked in "real bead solution", and when they are pulled out from the drilling hole with a needle, the appearance will fall off in pieces, and no fine scaly powder is found; Imitation beads with plastic coating: When the milky white plastic beads are coated with a layer of "real bead liquid", the surface will also fall off in pieces, and there is no fine scale powder. The non-glass substance under the skin can be felt on the surface of acupuncture. Usually, when two pearls rub against each other, the surface feels sandy, while when imitation pearls rub against each other, they feel smooth and have no sandy feeling-this is the easiest way to identify the authenticity of pearls. ?

I'm exhausted from typing so many words, so I have to make up some.