Gems must have the following characteristics: 1. "Beauty", that is, bright and shining, dazzling A gemstone cannot be a gemstone if it is not beautiful. This beauty is expressed in a brilliant color, or it is transparent and clean, or has special optical effects (such as cat eyes, color change, luminous, etc.), or has a special pattern ( Such as chrysanthemum stone, agate, plum jade, etc.). For example, diamonds, transparent and ensigns can be used to honour precious diamonds, while those with poor transparency, sturdiness and blackness can only be used as industrial raw materials. 2. "Long time", that is, the texture is hard and wearable, and it can last for a long time. Because of the high value of gemstones, one must expect it to be durable and can preserve even hereditary items. One of the reasons why diamonds are the most expensive gemstones is that it is the hardest and most corrosion-free gem in the world. Therefore, the most valuable gemstones in the world are some hard and corrosion-resistant silicate minerals (such as jadeite). , a small number of oxides (such as rubies, sapphires) and elemental minerals (such as diamonds), and soft, susceptible to corrosion of gemstones (such as jade, southern jade, etc.) itself is of low value, often used in the production of crafts, to win by work; But there are also a few gems not listed here, such as opal and pearls. 3. "Thin", that is, less production It is rare, the world's extremely rare emeralds, the highest quality is tens of thousands of dollars per carat (0.2 grams), and some beautiful and durable "long" stones (such as amethyst), due to production More, mining is easier, and its price has been lower. Some common rocks, after honing, are also aesthetically pleasing, but they cannot be a member of the gem family. The reason is that things are easy to get. Cotton Terry Fabric,Garment Cotton Fleece Fabric,Terry Towel Fabric,Printed Cottonterry Fabric SIRIS HOLDING GROUP CO.,LTD , https://www.sirisknitting.com