To distinguish the authenticity of tourmaline, we must first understand that the most common fake tourmaline materials are crystal, fluorite, glass and synthetic glass. Generally speaking, crystal is not as red and green as tourmaline, and crystal violet is more common, but tourmaline is purple instead of this violet! Therefore, the color difference between the two can be used to roughly distinguish between true and false. Distinguishing the authenticity of fluorite from tourmaline, the hardness of tourmaline is 7.5 Mohs, while the hardness of fluorite is only about 4 Mohs. The hardness of fluorite and tourmaline can be compared by drawing glass. Secondly, due to the low hardness of fluorite, the luster of fluorite jewelry is far less than tourmaline; Another point is that fluorite is often made of multi-color materials when posing as tourmaline, and tourmaline has no purple. Just when the multicolor of fluorite appears, it often has purple, so it is also an effective means to distinguish fluorite from tourmaline. The most obvious difference between glass and tourmaline is that from the internal inclusions, there are often small and round obvious bubbles in glass. If you see this feature, you can basically conclude that it is glass rather than tourmaline; There is another way for glass to pass off as tourmaline, that is, to pass off cracked glass as rough tourmaline. This kind of glass is usually dyed after bursting, so the color dyes are gathered in the gap, which is easy to distinguish by light transmission observation. There is also a phenomenon that tourmaline-like gems are synthesized from glass, which makes the glass surface look like tourmaline, but tourmaline has dichroism and birefringence, which glass does not have. As long as you carefully observe the contrast, you can find it. Moreover, tourmaline, which is generally used as a gem, has an appraisal certificate, and tourmaline that is pretending to be glass will not have a formal appraisal certificate. Extension: tourmaline: tourmaline is a kind of tourmaline that can reach the jewelry level. Tourmaline is a borosilicate crystal, which can contain elements such as aluminum, iron, magnesium, sodium, lithium and potassium. It is because of these chemical elements that tourmaline can show various colors. How to distinguish artificial tourmaline from natural tourmaline? Artificial tourmaline is mainly filled with glue. And this kind of filling fraud mainly occurs on some rough tourmaline carvings and beads! Because there are ice cracks inside this tourmaline, its air permeability is poor and its texture is rough and loose. It can be improved by injecting glue to cover up some cracks and impurities! The treated tourmaline has enlarged friction on the surface, and there are also cobweb-like corrosion traces similar to jade B. Moreover, the treated tourmaline is not bright enough, and its internal cleanliness is not good, which has the feeling of mixed colloid! One more thing, if it is tourmaline cut stone, then the brightness of tourmaline treated with glue on the reflective surface is not as good as that of natural tourmaline bare stone. Because of its good permeability and internal structure, the cut tourmaline is generally a high-quality natural tourmaline bare stone, with no impurities and cracks in its body and high transparency. If the tourmaline bare stone you see has these characteristics, generally speaking, it will not be treated.