Gemmological Characteristics of Jadeite and Its Crust from Muna Mine

Pharkant area is the most important jadeite origin in Myanmar,and Muna mine is one of the famous mines in Pharkant area.In this paper,by means of appearance observation,polarizing microscope and X-ray powder diffraction,the gemmological and mineralogical characteristics of jadeite and its crust from Muna mine were researched in detail,in order to provide relevant informations for follow-up studies about jadeite from Muna mine.The results show that the crust of jadeite from Muna mine is white to tawny and has fine sand crust mostly.The tactile impression of crust is sand-like or waxy.The crust of jadeite from Muna mine is thin,and the boundaries of jadeite and its crust are clear.The internal texture of jadeite from Muna mine is dense relatively,and the transparency of jadeite from Muna mine is pretty good.Flocculent ribbon is seen frequently in jadeite.The microstructures of jadeite from Muna mine are euhedral grain structure,including fibers interwoven structure,columnar crystalloblastic structure or inequigranular crystalloblastic structure.Jadeite is the main mineral of the crust and the jade from Muna mine.Besides the jade from Muna mine has green pyroxene,and the crust of jadeite from Muna mine contains kaolinite,pyrolusite,gibbsite,hematite and albite.