Shape classification:

(1) round beads

Refers to round pearls, which are divided into three types according to roundness, namely round pearls, round pearls and nearly round pearls.

The right ball refers to the ball with the best roundness, which is also commonly known as the walking ball in business. The ratio of the difference between the maximum diameter and the minimum diameter to the average straight diameter is less than 1%. A round pearl refers to a pearl with a very round shape, and the percentage of its diameter difference is between 1%-5%; Near-round pearls refer to pearls that are close to round pearls in morphology, and the percentage of diameter difference is between 5%- 10%.

(2) oval beads

Refers to the oval pearl whose length-diameter ratio is greater than 10%. It can be further divided into short ellipse and long ellipse according to the percentage of long and short diameter difference, and the percentage of long and short diameter difference of short ellipse is10% ~ 20%; The percentage of the diameter difference of the long ellipse is greater than 20%.

⑶ Flat bead

Refers to a plane shape with one or two sides, such as oblate circle, oblate ellipse, pie shape, diamond shape, square, etc. This kind of pearl is most suitable for making pearl beads.

(4) Ma Bizhu

It is a kind of semi-bead, also known as Mabeizhu, steamed bread bead and semi-round bead, also known as Mabeizhu.

5] shaped bead

In addition to round beads, oval beads and marbi beads, there are many pearls with different shapes. Pear-shaped pearls, drop-shaped pearls, rice-shaped pearls, potato-shaped pearls, bean-shaped pearls and other pearls are collectively called shaped pearls in business.