First, natural jewelry and jade.
According to the causes and composition, it can be divided into:
1, natural gems: diamonds, rubies, sapphires, emeralds, etc.
2. Natural jade: jadeite, nephrite, jadeite and so on.
3. Organic gems: pearls, corals, amber, etc. Cultured pearls also belong to this category.
Second, man-made products.
It is completely or partially produced or manufactured by human beings and used as materials for jewelry and decorations.
1, synthetic gems: synthetic emeralds and synthetic rubies;
2. artificial gem: artificial yttrium aluminum garnet, artificial strontium titanate, etc. ; So far, the natural science office has not found this mineral;
3. Spliced gems: gems and jade that are made of two or more materials by hand, giving people an overall impression;
4. Recycled gems: The fragments or chips of natural jewels and jade are welded or pressed into jewels and jade with an overall appearance by artificial means, such as recycled amber and recycled turquoise.
Third, imitation gems.
It is an artificial product that imitates the color, appearance and special optical effects of natural jewelry and jade. Such as imitation diamond, imitation jade and so on.
Identification method:
1, color: Jade experts attach great importance to color. Color is not only an important criterion for evaluating the quality of jade, but also the main basis for classifying jade types.
2. Hardness: Hardness is one of the important signs to identify jade. The hardness of minerals is a mechanical property of minerals to resist the invasion of other objects. There are usually two kinds of hardness:
(1), the relative hardness, or Mohs hardness, is a kind of scratch hardness.
(2) Absolute hardness, also called indentation hardness. According to the weight that the mineral surface can bear. The Mohs hardness of Shetaicui is between 6.9 and 7.2, with slight differences among different varieties. Generally speaking, the hardness of white jade is slightly greater than that of jadeite. In the jewelry industry, hardness is generally regarded as an important symbol to distinguish gems from jade. The hardness of gemstones is generally above 7.3 degrees Mohs, and that of jade is generally between 4 and 7.2 degrees Mohs. She Taicui has high hardness, good grindability and easy preservation, and has certain collection value.
3. Density: Density is the weight of jadeite per unit volume. She Taicui's weight measured with a small weight sample is 2.65 ~ 2.85. Different varieties are slightly different, white jade 2.85, blue white jade 2.65 and jadeite 2.75.
4. Transparency: Transparency is the degree to which jade allows visible light to pass, which is mainly related to the absorption of light by jade. Mineralogy can generally be divided into four types: transparent, translucent, micro-transparent body and opaque. She Taicui belongs to micro-transparent body, which can transmit light under the general enterprising degree, but can't see the transparent objects clearly.
5. Gloss: Gloss is the ability of jade to reflect light. Her brittle luster belongs to glass luster. This luster is neither strong nor light, that is, there is no crystal inspiration of strong light, nor wax texture of weak light, and it is soft, delicate and shiny.