Make sure you buy real diamond products. For example, diamond rings and diamond pendants can be used on a large scale. I usually buy from EONDI jewelry (www. eondi.com )。 Good quality and affordable. Common diamond identification instruments or tools mainly include: gem magnifying glass, gem microscope, polarizer, spectroscope, thermal conductivity instrument, etc. Principle of use of magnifying glass: Magnifier is the most important and simplest tool for gem identification, which is mainly used to observe the internal and external characteristics of gems, including crystal shape, growth texture, fracture, inclusion, cutting ratio and so on. In gemmology, a magnifying glass with a magnification of 10 is generally used. Magnifier with 20 times, 30 times and 50 times has large magnification, small field of view, short focal length and difficult operation. 10 times the use of magnifying glass: one hand holds the magnifying glass, and the other hand holds the gem with tweezers. The distance between the magnifying glass and the eye is about 2.5cm, and the gem is about 2.5cm (the greater the magnification, the smaller the distance should be). Observe the rotating gemstone with side light and dark background without reflection, and adjust the distance between the gemstone, magnifying glass and eyes at any time. Clearly observe the internal and external characteristics of the gem, such as crystal, growth line, cutting ratio, etc. From all directions. Thermal conductivity meter: Thermal conductivity meter is an instrument to identify imitations such as diamonds according to their thermal conductivity. The thermal conductivity of diamond is extremely high, while that of other gems is mostly low, so the thermal conductivity meter is mainly used to distinguish diamonds from other imitations. When the probe of the thermal conductivity meter touches all kinds of gems, the thermal conductivity meter will give instructions.