The size, roundness, gloss and flaws of pearls are all top-grade products with large particles, round luster and no flaws.

A 1: shape grade: perfect circle is A 1. (Diameter difference percentage is less than or equal to 1)

A: Glossy: extremely strong. A. Reflected light: especially bright, sharp and uniform, with a mirror-like surface and clear images.

A: thickness of weld seam layer: ultra-thick is a. & lt The thickness (mm) of the weld layer is greater than or equal to 0.6 >:& gt；;

. Smooth finish: flawless A. (Pearl skin: the surface is smooth and delicate, and it is extremely difficult for the naked eye to see that the surface is flawed)

Nanyang Pearl Nanyang Pearl refers to pearls produced in Southeast Asia, Indonesia, Persian Gulf, South Pacific, Australia and other places. It is mainly cultivated by Pinctada maxima and other Pinctada, and the shell is the largest pearl-producing shellfish.

Nanyang pearls are cultured in seawater, which has a long culture time and low survival rate. But the cultured pearls have beautiful luster, large particles and high value. Jewelry inlaid with a single pearl can often sell for thousands to tens of thousands of yuan. Among them, black pearl is a very popular variety in recent years. Fake pearls are mostly made of plastic.

Pearls are divided into seawater pearls and freshwater pearls.

Seawater:

1. Shape grade: the perfect circle is A 1. (Diameter difference percentage is less than or equal to 1)

2. Gloss: A is extremely strong. Reflected light: especially bright, sharp and uniform, with a mirror-like surface and clear image.

3. Thickness of bead layer: the extra thickness is a .. < < Thickness of weld layer (mm) is greater than or equal to 0.6 >: >;

4. smoothness: flawless is a. (pearl skin: the surface is smooth and delicate, and it is extremely difficult for the naked eye to see that the surface is flawed)

* Percentage of the difference between the maximum and minimum diameters of pearls and the difference between the average values of the maximum and minimum diameters.

Fresh water:

1. Shape level: circle type: perfect circle is A 1. (Diameter difference percentage is less than or equal to 3)

2. Gloss: A is extremely strong. (Reflected light: especially bright, sharp and uniform, and the image is very clear)

3. Smoothness: flawless is A. (Pearl skin: the surface is smooth and delicate, and it is extremely difficult for the naked eye to see that the surface is flawed)

4. It is good to have a matching degree: the quality factors such as shape, luster and smoothness should be uniform. Colors and sizes should be harmonious and beautiful or gradual. The eyelet is centered, straight, smooth and free of burrs.

* Freshwater beads are classified as seawater beads.