Why do pearls turn yellow and fade?

If a woman must have a piece of jewelry, it can be said to be a pearl. The pearl symbolizes nobility, elegance and temperament, giving people a feeling of softness, gentleness, and virtuousness. The smooth and moist surface and the round and soft appearance. It is reminiscent of women's smoothness. If a woman must have a piece of jewelry, it can be said to be a pearl. The pearl symbolizes nobility, elegance, and temperament. It gives people a soft, docile, virtuous and quiet feeling, that is smooth and moist. The surface and the round and soft appearance reminds people of women's smooth and smooth skin and beautiful lines. Pearls are regarded as the incarnation of women. Why are pearls so beautiful that they turn yellow and fade?　　 Although the color of freshwater pearls is beautiful, it can't stand the test of a long time. Generally after more than ten years, the pearl will turn into an ordinary yellow and lose the beautiful freshwater pearl luster. This is the old yellow pearl as the saying goes.　　　　 Why does freshwater pearl jewelry turn yellow after being used for a long time? This is mainly because the physical properties of the aragonite mineral that make up pearls are unstable. Over time, it will become ordinary calcite. Although aragonite and calcite have the same chemical composition, their crystalline form and luster are different. This is why the pearl changes color.　　　　 Why do pearls turn yellow when they are old? This means that pearls have a longevity, and yellowing is a sign of aging of pearls.　　　　Pearls have always been regarded as treasures. In ancient tombs across the country, ancient pearls are often unearthed, but ancient pearls have never been taken seriously by collectors. In the beginning, after the death of wealthy women, especially the ladies and young ladies who died young, they often buried their favorite pearls together. Like humans, the pearls are young and shiny, but when they are unearthed, they are withered and yellow. They have lost their old style and are no longer cherished.　　　　 pearls are bred by pearl mussels, and their luster and pearls have a certain life span. Although the life span is longer than that of human beings, the nacreous layer is oxidized in the air over time, turning from white to yellow. Even if the pearls buried in the soil were well preserved in the coffin, they will lose their unique luster. Cracking of the nacre, if the coffin enclosure is not well sealed, it will usually become a pile of residue. On Qianlong’s little hat, there is a big pearl, passed down from generation to generation to the hand of the last emperor Pu Yi. After more than two hundred years, it is still very intact, but in terms of brilliance, it is already a yellow pearl. Its collection value is mainly reflected in the emperor's experience, which is difficult to preserve forever.　　　　 According to modern scientific research, it is known that pearls are calcium carbonate crystals combined with special colloids of shellfish. Each pearl contains more than 90% calcium carbonate and about 4% moisture. Pearls rely on this moisture to make them shine. Pearls that have not been used for a long time will easily run away from the water, and will turn yellow after about 60 or 70 years or more than 100 years. This shows that the life of pearls is not long. A pearl has about a hundred years of opportunity to show its brilliance. It is also very lucky compared to the unknown one in the deep sea.　　　　 The above is the information about pearls summarized by the author for you. The information comes from the Internet. If there is anything wrong, please understand. If you need knowledge and understanding of pearl setting, please pay attention to the official website of jewelry setting. Jewelry setting is waiting for your inquiry!