(1) According to the reasons for the formation of pearls, it is divided into natural pearls and artificially cultured pearls.
Natural beads. The pearl that is naturally produced by wild shellfish.
Cultured beads. The pearls produced by artificial cultivation and breeding are cultured pearls. The cultured pearls are artificially implanted into the inner side of the shell of the shellfish by artificially implanting hemispherical or three-quarter spheres and other non-spherical beads, so that the shellfish are exposed to foreign objects. Stimulating, constantly producing secretions, after a period of time, the secretions of the shellfish in vivo will be wrapped into the beads or beads, bonded, and gradually formed a bead layer, the cultured pearls are thus formed. In the cultured beads, there are two types of non-nuclear pearls (ie, cell beads) and nuclear beads.
(2) According to the water quality produced, it is divided into freshwater pearls and seawater pearls.
Freshwater Pearls. Produced by the Tamsui River.
(3) According to the color, there are white, gold, silver, pink, red, black, blue, gray and other colors, among which white is slightly reddish and red is the best, and blue and black with metallic luster is especially good, but if you see Obvious black and gray pearls should be vigilant and may be stained beads. The method of distinguishing dyed and true color pearls is: natural black pearls are not pure black, but dark blue black with a rainbow-like glitter, or black with a bronze hue; dyed pearls are grayish black and black, with monotonous color and poor gloss. If the pearl is scrubbed with a little 5% dilute nitric acid in the cloth, black marks will remain on the cloth. Consumers should pay special attention when purchasing expensive black pearls.
(4) According to the shape, it is divided into round bead, elliptical bead, semicircle, egg shape, pear shape, drip water, conjoined body, baroque shape, deformed bead, and deformed bead is divided into symmetric deformed bead and asymmetric deformed bead. Round beads This is the most ideal pearl. In ancient times, China was called "walking beads", that is, it was placed in the disk and moved slightly. Other forms of pearls also have their value and the appreciation of people.
(5) Divided into PCT beads (2.0--5.0), water beads (5.0--5.5), medium beads (5.5--6.5), large beads (6.5--7.5) extra large beads (7.5--8.5) , super extra large beads (> 8.5).
(6) According to the place of origin, it is divided into Dongzhu, Xizhu, Nanzhu, Australia, Persian, Mannar and so on. In the Ming Dynasty, Qu Dajun's "Guangdong New Language" had "Hepu Pearls, Nanzhu, and Western Europeans were Xizhu, and Dongyang was Dongzhu. Dongzhu was not as good as West Pearl, and West Pearl was not as good as Nanzhu." It can be seen that as early as the Ming Dynasty, "Nanzhu" has become the special name of Hepu Pearl.
(7) According to the use, it is divided into medicinal beads and decorative beads.
(8) According to the mother of the output pearl, it is divided into Marsh shell pearl, black butterfly shell pearl, white butterfly shell pearl, penguin shell pearl, abalone shell pearl and so on.
(9) According to whether there is any approval, it can be divided into nuclear beads and non-nuclear beads.
(10) According to the position of the bead, it is divided into free beads and shell beads.
(11) According to the thickness of the bead layer, it can be divided into thick bead and thin bead. For different types of pearls, the diameter of the pearls is different, and the thickness of the nacre is different.
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