Abstract:
This paper presents a new viewpoint that there exists the desalinization of chromium within the Myanmar jadeite jade,which plays an important role in genesis and evolution of green colour of the jadeite jade.The desalinization of chromium within the Myanmar jadeite jade is divided into four stages:(1) transformation from chromite to kosmochlor,which is characterized by the metasomatic reaction,forming corona texture or granoblastic texture;(2) from kosmochlor to chromian jadeite,which is regarded as the replacement reaction,accompanied by metasomatism;(3) from chromian jadeite to low chromium-bearing jadeite(
w(Cr
2O
3)=±0.3%),which is the replacement reaction accompanied by recrystallization induced by deformation, and(4) from chromium-bearing jadeite to lower chromium-bearing jadeite,which is essentially the further evolution of the stage 3.The desalinization of chromium within the Myanmar jadeite jade is influenced by variety of neighbor minerals,the way and intensity of deformation/metamorphism induced by shear stress,
p/t condition and fluids.Using the desalinization of chromium,the feature that green colour in jadeite jade has special shape can be interpreted,and how and what the green colour changes can be understood.