2. Emerald is bicolor. From different directions, gemstones are turquoise-blue-green or yellow-green, while glass and YAG have only one color.
Most of the differences between natural emeralds and synthetic emeralds need to be made in the laboratory. Their general differences mainly include:
(1) The refractive index of natural emeralds is generally between 1.57- 1.59, while the refractive index of synthetic emeralds is generally lower, generally less than 1.57, but there are exceptions.
(2) The specific gravity of natural emeralds is more than 2.7, while the specific gravity of emeralds synthesized by melting method is only about 2.65-2.66. However, it should be noted that some emeralds synthesized by hydrothermal method also have a high proportion.
(3) Most natural emeralds have defects and three-phase inclusions, while emeralds synthesized by needle-shaped, columnar and granular crystal mineral inclusions are often clean. Emerald inclusions synthesized by hydrothermal method are "window screens", while crumbs are synthesized by melting method. The inclusion characteristics of natural emeralds and synthetic emeralds are different
(4) Natural emeralds react slowly under ultraviolet light, or are dark red, while synthetic emeralds tend to emit strong red fluorescence. Generally speaking, this test should be compared with the standard sample.
Extended data:
Keep common sense:
(1) Don't contact with acid or alkali, and don't rub with other precious stones or metals to avoid scratching the surface of precious stones.
(2) clear water. Emerald is usually treated by oil immersion to cover up cracks and increase transparency. Therefore, when cleaning jade ornaments, if acid, alkali, alcohol, ether, etc. The filler material in the feather cracks will be destroyed and its transparency will be reduced. Therefore, it is best to wash jade ornaments with clear water. Emerald jewelry can't be cleaned by ultrasonic wave, otherwise it may cause irreparable loss to the gem.
Baidu encyclopedia-emerald