Gemological Characteristics and Color Origin of Black Cyan Serpentine from Xinjiang Region
Xinjiang black cyan serpentine is a new jade variety that has recently appeared on the market,and people′s awareness of it is relatively weak compared to other colors of serpentine.In this paper,Xinjiang black cyan serpentine is taken as the research object.On the basis of its conventional gemmological characteristics and studies under polarized light microscope,its mineral composition,chemical composition,structures,textures and spectroscopic characteristics are systematically studied by using X-ray powder crystal diffraction technology,EPMA,and infrared spectroscopy,raman spectroscopy,UV-visible spectroscopy as analytical tests.At the same time,the cause of its black cyan coloration is also analyzed.The results show that the main constituent minerals of black cyan serpentine are the serpentine group minerals antigorite,with a small amount of lizardite,calcite and magnetite.Serpentine is rich in iron and poor in magnesium.Black cyan serpentine is mainly of fibrous metamorphic structure,locally with scale-like metamorphic structure.Its infrared and raman spectral characteristics are consistent with those of antigorite,and the black cyan color is mainly related to the content of Fe in serpentine.The black cyan color of serpentine is due to Fe3+ d-d electron transition and charge transfer between Fe2+→Fe3+.
国家科技期刊平台
NSTL
万方数据
维普
