Ruby identification can be divided into two steps. The first step is to distinguish rubies from other rubies. The second step is to distinguish natural rubies from artificial rubies. The main difference between ruby and other rubies is to test its refractive index and light convenience. Hardness test is suitable for raw stone. One way is to measure its refractive index. The refractive index of garnet is similar to that of ruby, and the refractive index is between 1.74- 1.75, which is lower than that of ruby. Sometimes Fe-Al-Mg-Al garnet may be mixed with rubies made in Thailand, but the colors are very different. Secondly, except for artificial ruby and red tourmaline, other red varieties have no dichroism. The dichroism of red tourmaline is similar to that of ruby, but under Chelsea filter, red tourmaline does not show red fluorescence (note that the redness of a few red tourmalines is caused by chromium, and fluorescence reaction can be seen under the filter. But can be distinguished from hardness). As long as you look carefully, it is not difficult to distinguish the second floor stone. That is, remove the jewelry from the holder, put it in a bottle filled with water, and observe it carefully from the waist of the gem. Because the two layers of stones are composed of two red varieties, the colors are very different, which is easy to see in the water. In addition, observing the waist with a magnifying glass of 10 times, you can see the bonding lines and bubbles at the bonding place. Another reliable method is to measure the refractive index of the upper and lower layers, and the difference is two layers of stones. After distinguishing rubies from other rubies, the second step can be carried out, that is, distinguishing natural rubies from artificial rubies. The method is to observe carefully with a magnifying glass first and find doubts. Then use various means, various equipment and instruments to check. Then, in fact, natural products and artificial products can be roughly judged by experience according to the feeling at first sight. If the artificial products are very pure and have good transparency, they will have a fleeting rosy hue, and natural products are not easy to appear. In addition, if there are individual independent black carbon spots and patches on the surface or shallow part of ruby raw materials or finished products, they are all artificial rubies. Furthermore, some natural rubies with white spots and uneven colors are genuine. Finally, the six star lines of the artificial starlight Hongbao antiquities are conspicuous. The star lines extend to the lower part of the gem, and natural white fog can be seen on the surface. However, even if you have seen the authenticity, before you actually buy it, if possible, you must carefully check it with several instruments. Because people's judgment ability is often influenced by many natural and human factors. The method of identifying ruby by food has been reported in foreign works, and the method is similar. She made several tests on high-value rubies. But the most important thing is to correctly judge the observed phenomenon, otherwise there will be mistakes. Natural ruby is a trigonal crystal system, and its growth lines are all straight lines, which are parallel to the crystal plane and intersect with the straight line, and the intersection angle is 120 degrees. Artificial products grow in an inverted pear shape. Therefore, it is a dense curved pattern, much like the groove pattern on a record. If the growth line cannot be observed with a magnifying glass, pure diiodomethane can be used as the immersion liquid (the refractive index is similar to that of ruby). Put a developing photographic paper on the bottom of the bottle containing diiodomethane solution, put the ruby face down on the photographic paper, and use appropriate lighting. If developed correctly, even transparent and colorless corundum will show long lines (which should be carried out in a dark room), which is one of the very reliable identification methods. Ruby is rarely complete, and usually contains small crystals of other minerals and fine needle-like red rutile reflective fiber bundles. Some small gaps containing liquid and small tubes with irregular fragments can be observed. With a magnifying glass or microscope, it is the real thing that can see these contents. But be careful not to mix it with the dark crystal impurities of artificial ruby and the spherical or slender bubble characteristics common in artificial products. Such bubbles are rare and sometimes appear in groups. If you look at it with light, you can see that it is milky white and very bright. Although it is difficult to distinguish it from natural products, it is easy to distinguish it with more experience through long-term observation. Natural rubies often contain a large number of trace elements that cannot be prepared artificially, which inhibits the penetration of short-wave ultraviolet rays into natural rubies. Artificial rubies with pure short-wave ultraviolet rays are easy to penetrate. Using this principle, we can put a developing photographic paper in a flat water bottle, a ruby under the photographic paper, a short-wave ultraviolet lamp 20 cm above the photographed ruby, and expose it in a dark room for a few seconds. As long as the exposure is accurate, the natural ruby is white on the developing photographic paper, indicating that ultraviolet rays do not penetrate. Cultural relics are dark, with only a white circle on the edge, indicating that ultraviolet rays can penetrate. When cutting and grinding natural rubies, in order to obtain the best color effect, the mesa must be perpendicular to the optical axis of the ruby, so it is single refraction from the top surface of the ruby without dichroism. On the other hand, artifacts can observe strong dichroism from the top. However, in some backward areas, in order to maintain the maximum weight of rubies, the directionality is not considered when polishing. Therefore, this identification method cannot be used to distinguish authenticity alone. Natural products with dark or uneven colors and shadows can be regarded as genuine products. At or near the junction of artificial ruby facets, common crack marks, called burn marks, are caused by local overheating during polishing. Careful observation shows that there are more cracks than traces, so we must check them by other methods. The natural ruby produced in Myanmar has no phosphorescence when observed by ultraviolet lamp or cross filter. Artifacts will have phosphorescent residual light for a period of time (in a dark room). However, a few natural products will also have short-lived phosphorescence, so we should pay great attention to the difference. Natural rubies made in Thailand have no fluorescence and need to be tested by various methods. Because most rubies have fluorescence reaction, foreign jewelry stores often install ultraviolet devices, so that rubies can find a beautiful light like fire, and buyers can't put it down. But the takeaway shop is far less brilliant than the store. Therefore, if you want to buy rubies in this case, you must take them outside the store and observe them in the sun before buying them.