Hello, I am engaged in jewelry appraisal. The point measurement means that the refractive index of this gem is about 1.6 1, just referring to what kind of gem it is. Due to the structure of nephrite, the field measurement data is not particularly clear, generally around 1.62, and the measured value of 1.60 is within the normal range, so it is impossible to judge the quality of jade. The quality evaluation of jadeite is mainly color. If it is white jade, the better. If it is jasper dark green, topaz beeswax has the best color. Secondly, the texture, that is, the degree of exquisiteness, is greasy to the touch; And shiny. If it is waxy luster, it means that the particle structure is rough, the texture is not good, it will oxidize and become darker and darker, and the stronger the grease luster, the better; There is also transparency, and generally good hetian jade is slightly transparent. Only in this way can we judge the quality of a piece of Hetian jade. You can keep asking me questions.