Grade A Jadeite
Grade A jadeite (also known as type-A jadeite)refers to the natural jadeite which has not been processed through physical or chemical method and the internal structure of the jadeite is not destroyed. Grade A jadeite is solely produced from the natural world and it is processed and pondered normally.
The characteristics of natural jadeite are as the following:
The proportion of jadeite: 3.25 – 3.35;
The Mohs hardness of jadeite: 6.5 – 7;
The melting point of jadeite : 900° C – 1000° C;
The refractive index of jadeite : 1.65 – 1.67.
There would be an obscure shadow boundary on 1.66 of the refractometer.
The luminescence of the jadeite: Light colour jadeite will show dim and florescent white light under the long-wave ultraviolet light, and there would be no reaction under short-wave ultraviolet light.
Other grades of jadeite are not 100% natural and valueless except grade a jadeite. They are including Grade B, grade C, grade B+C,grade D.
Grade B jadeite: This is natural jade, but soaked in an acid solution that is highly concentrated. It is then soaked in epoxy resin and hardener. It is then taken out and heated to allow it to harden. The treatment improves transparency and the color of jade. By so doing, the texture and durability are decreased. This grade is also referred to as natural color jade as it isn’t dyed.
Grade C jadeite jade: This is also called dyed or colored jade.
Grade B+C: This is acid rerated and then filled with resin. After this, greater transparency and beautiful color are achieved on the jade. However, this color isn’t natural and neither is the jade as durable.
Grade D jadeite jade: This grade isn’t real jade. It is a stone that really resembles jadeite jade. It can be sold as a jade imitation but it isn’t the real thing.