The mantle of the clam is stimulated by the invasion of foreign matter (sand grains, parasites). The epidermal cells in the stimulated area use the foreign matter as the nucleus and sink into the connective tissue of the mantle. The trapped part of the mantle epidermal cells spontaneously The pearl sac divides to form a pearl sac, and the pearl sac cells secrete nacre, which coats the core layer by layer to form a pearl.

Artificially cultured pearls are based on the above principles and use artificial methods to cut small pieces of living epithelial cells (referred to as small cell pieces) from the mantle of pearl-breding clams, together with the artificial core prepared from the clam shell. Implanted into the connective tissue of the clam's mantle, the implanted cell fragments rely on the nutrients provided by the connective tissue to rapidly proliferate around the artificial nucleus, form pearl sacs, and secrete nacre, thereby producing artificial nucleated pearls.

Artificial nucleated pearls are produced by implanting only small pieces of cells into the mantle during surgery. The cells multiply to form pearl sacs and secrete nacre into the sacs. Extended information

Shape classification:

1. Round beads

Refers to pearls that are round in shape. They are divided into three types according to their roundness, namely perfect round beads. , round beads and nearly round beads.

2. Oval beads

Refers to oval-shaped pearls with a length-to-diameter ratio greater than 10%. It can be further divided into short ellipse and long ellipse according to the percentage of long and short diameter difference. The percentage of long and short diameter difference of short ellipse is 10% to 20%; the percentage of long ellipse diameter difference is greater than 20%.

3. Flat beads

refers to flat beads with one or two sides that are approximately flat, such as oblate round, oblate oval, pie-shaped, rhombus, square, etc. . This type of pearl is most suitable for connecting pearl beads.

4. Mabe beads

It is a kind of half-sided pearl, also known as Mabe beads, steamed bun beads and semi-round beads, also known as Mabe beads. Beads.

5. Special-shaped beads

In addition to round beads, oval beads, and Mabee beads, there are also many other pearls with different shapes, such as pear-shaped, drop-shaped, rice-shaped, Potato-shaped, bean-shaped and other shaped pearls are commercially referred to as special-shaped pearls.

Baidu Encyclopedia-Pearl