"Beauty" means gorgeous, crystal clear and dazzling. If a gem is not beautiful, it can't be a gem. This kind of beauty is either colorful, transparent and clean, or has special optical effects (such as cat's eye, color change, night light, etc.). ), or have special patterns (such as chrysanthemum stone, agate, plum blossom jade, etc. For example, both of them are diamonds, and those with few transparent defects can be polished into precious diamonds, while those with poor transparency, many defects and black color can only be used as industrial raw materials.

"Long" means hard and wear-resistant, and can last for a long time. Because of its high value, people must expect it to be durable, valuable and even heritable. One of the reasons why diamond is the most expensive gem is that it is the hardest in the world and is not afraid of corrosion. Therefore, most of the high-value gems in the world are silicate minerals with high hardness and corrosion resistance (such as jadeite), a few oxides (such as rubies and sapphires) and elemental minerals (such as diamonds), while the soft and corrosive gems (such as xiuyan jade and Southern Jade) are of higher value. But there are also a few precious stones that are not included, such as opals and pearls.