Apart from professionals, few people seriously discuss the meaning of jewelry. They are used to calling jewelry, handicrafts or other valuable treasures made of natural materials (minerals, rocks, organisms, etc.) jewelry. ) gold and silver are used as jewelry, so there is the saying of "gold and silver jewelry", and the jewelry stores that operate these items are also collectively referred to as "jewelry stores". Scientifically speaking, the concept of "jewelry" is the same as "gem" in a broad sense. Gems in a broad sense generally refer to those raw materials suitable for polishing or carving into jewelry or handicrafts. However, is the granite that can carve stone lions also a gem? The answer is no, because, as a gem, it must have the following characteristics:

First, "beauty" is 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. Knowing this, we can understand why both of them are diamonds. 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.

The second is "long", that is, the texture is hard and wear-resistant, and it 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.

Third, "sparse", that is, less output. Rare things are precious. Emerald, which is extremely rare in the world, is worth tens of thousands of dollars per carat (0.2 g) because of its superior quality, while some beautiful and "enduring" gems (such as amethyst) have always been low in price because of their large output and easy mining. Some ordinary rocks, after pondering, also have the characteristics of beauty and durability, but they cannot become a member of the gem family. The reason is that things that are easy to get will be cheap.

So, what do gems in a broad sense include? It includes inorganic gemstones and organic gemstones.

Inorganic gemstones are divided into natural gemstones and artificial gem. Natural gems refer to gems formed in natural geological processes, and rocks formed by single mineral crystals or many single and complex minerals, such as diamonds, rubies, sapphires, olivine, crystals (single minerals), jadeite, nephrite (rocks) and so on. Artificial gem includes synthetic gems and fakes (also called imitation gems). Synthetic gemstones are "inorganic gemstones" synthesized in laboratories or factories according to the chemical composition and physical and chemical conditions of a natural gemstone. Their physical and chemical properties are the same or basically the same as those of natural gemstones, such as artificial diamonds, artificial rubies and artificial crystals. Counterfeits refer to plastic, glass and other products or inorganic compounds whose appearance is similar to some gems, and their physical and chemical properties are not related to similar gems that do not exist. These items include cubic zirconia imitation diamonds (so-called "Soviet diamonds"), plastic imitation pearls, green glass imitation jade and so on.

Organic gems refer to the gems whose formation is related to biology or biological action, such as coral, pearl, amber and so on.

It can be seen that the word "jewelry" includes all the above items.

What do precious stones mean in a narrow sense? Especially those gems that are composed of single mineral crystals, such as diamonds, red (blue) gems, olivine, crystals, etc. Rock gems composed of many single and complex minerals are classified as jade; Professionals often use this name: gem, jade, or collectively referred to as "gem", from which the subject name "gemology" is derived.