Everyone knows that all jewellery products have a grade, that is, a product grade. As with the development of diamond grade identification standards, GIA has also established standards and terminology for the identification of pearl grades. How to judge the quality grade of pearls, GIA's pearl grade identification system was introduced in 1998, which specifies the following seven factors affecting pearl value: gloss, roundness, smoothness, bead (nuclear pearl), size, color and Matching, we can grade the quality factors from these seven aspects. 1, luster GIA believes that among the seven factors that determine the value of pearls, luster is the most important. The so-called "pearl treasure", the luster is the soul of the pearl. The variety of pearls varies and the gloss is also very different. Gloss gives the pearl its unique beauty. The luster of the pearl is due to the reflection of light on the surface of the nacre formed by many calcium carbonates. People face the light source, such as windows, doorways, etc., put the pearls in front of them, and look at the light, good pearls can see the colorful rainbow light, the layers are rich and varied, you can also see the spherical surface like metal It can even reflect the pupils of the person, especially brighter can be included in the A grade, followed by the B grade. The same grade of luster, seawater pearl luster is brighter than freshwater pearl. 2, roundness Pearls come in eight basic shapes: round, nearly circular, button-shaped, drop-shaped, pear-shaped, oval, baroque and oblate. "Beads and jade", the more beautiful the pearl, the more aesthetic habits of most people. Large particles and round pearls show the beauty of the moon. With the luster, it creates a beautiful artistic conception. The percentage of the longest diameter and the shortest diameter difference of the pearl is ≤1%, the standard is 1%≤the diameter difference ratio is ≤5%, and the circle is between 5% and 10%. Under normal circumstances, you can see the roundness with your own eyes. Perfect round pearls are the most precious, but there are exceptions. With the constant personalization of aesthetics, well-formed pear-shaped, oval or baroque cultured pearls are also regarded as treasures by pearl lovers. In addition, because the seawater pearls are nucleated and cultured, the shape is relatively good, so generally the roundness of the same grade, the roundness of seawater pearls is better than that of freshwater pearls. 3, smoothness GIA evaluates the number of defects on the surface of the pearl to judge the quality. If the surface features of the pearl are numerous or very obvious, it will affect its robustness and seriously reduce its value. If the surface characteristics are not obvious, or are extremely subtle and can be masked by drilling or inlaying, then it has less effect on the appearance and value of the pearl. The less thread, the spot, the print, the pit, and the point of the pearl surface are of higher quality. Generally, the standard is not acceptable at 0.5 meters away. 4, the bead layer Bead thickness: The vertical distance from the outer layer of the bead core to the surface of the pearl. Gloss is closely related to the quality of the nacre. In addition, if the nacre is very thin, the firmness of the pearl will also decrease, and the pearl may appear peeling after a long time. At present, methods for detecting bead layers include X-ray photography, OCT optical coherence chromatography, bead thickness detection methods, and direct measurement methods. 5, size The diameters of pearls currently on the market range from 2 mm to 16 mm. Generally speaking, the larger the pearl, the rarer the quantity, and the price tends to multiply. Different varieties vary in size. At present, Nanyang Pearl is the largest and the price is the highest. 6, color The color of the pearl is divided into white, red, yellow, black and other five series, each series includes a variety of body color. The color of the pearl varies from species to species. Although white is the most classic color, more unusual natural colors, such as black and gold, are increasingly popular due to rare and rare. People's pursuit of a certain color of pearls will also affect the value of the pearls, so the malachite green Tahitian black pearls, pure white background with pink colorful color with pearls and no variegated pure gold price It will be more expensive. 7, match This one of the GIA settings is a bit special, specifically for jewelry containing two or more pearls. For jewelry made up of pearl strings and multiple pearls, the degree of matching (or blending) of the pearls affects the value. Jewelry designers sometimes deliberately mix colors, shapes and sizes to create unique effects, but for most pearl strings, earrings or other pearls made of pearls, the pearls should meet all quality requirements. The above is the standard for the classification of pearl quality. Consumers can evaluate the quality of pearls according to the above criteria when purchasing pearl jewelry, and then choose what they like. Zhejiang Yijue Import And Export Co., Ltd. , https://www.yijuecashmere.com