The Main Reason of Jade Contamination in the Burial Sites:

1. Natural soil chemicals which were activated by the ground water.

2. Corrosion products like iron and bronze objects added to the burial site.

3. Products of the organic type in burial additions and the body itself of the deceased.

4. Chemicals like red chalk, a reddish ferro oxide compound, which were often used in large quantities around the tomb (red chalk 5. Is an reddish iron oxide mineral from Hämatit (fe2o3).

6. Further on the chemical influence of mercury additions which coloured the jade deep brown to black

7. And finally high temperatures from fire burials.

All these conditions were known to the ancient chinese culture and due to the same, they took corresponding measures to keep jade artefacts intact for longer time. So the jade article’s surface was conserved with hot wax and/or in boiling grease/wax. These wax and layers of fat, depending on ground aggressiveness and storage of the artefacts, sometimes lasted for centuries in form of strong encrustations on its surface.

Therefore, many ancient jade artefacts have a greasy and russet, sometimes mixed with grease and sand smeared surface, which will appear after cleaning the artefact. Engravings, cracks and deepening which were closed by the wax, sometimes look as new. Therefore it is always important to judge the complete surface about the genuineness of an ancient jade object, which could very, depending on the earlier preservation measures.

As per the opinion of the chinese jade experts, all jade artefacts will have to be first cleaned and then conserved with wax, to gain the natural colour of the stone as far as possible.