The Study On Gemological And Mineralogical Characteristics Of Nephrite In Sangpiyu, Liaoning Province

Sangpiyu nephrite deposit is located in Sangpiyu village, Xiuyan county, Anshancity,Liaoning province. The deposit was the product of metasomatism which betweenmagnesian carbonatite and later period magmatic hydrotherm of intermediateacidigneous rock. This thesis did research into mineral composition, structure andspectroscopy characteristics of Sangpiyu nephrite deposit by scanning electronmicroscope, electron probe and X-ray powder diffraction, infrared spectrum andRaman spectrum method.Sangpiyu nephrite has varieties of colour include light green to dark green andare uniformly distributed. The nephrite has white weathering crust on surface. Darkgreen ribbon and dark spots can be found in dark green nephrite.The microstructure of Sangpiyu nephrite include felt structure, microscopicfibrous structure and microscopic fibrous crystalloblastic structure. Tremolitemineral grains’ mainly shape are fibrous, lamellar, microscopic radial, needlecylindrical and porphyritic and grain is fine. Tremolite and carbonatie mineral crystalsare mixed in the contact zone,where metasomatic relict texture can be found.The main mineral composition of Sangpiyu nephrite is tremolite, secondaryminerals composition including calcite, pyroxene, apatite, epidote, pyrite, etc. Theprincipal sorts of Sangpiyu nephrite are SiO2、MgO and CaO，low FeO content, andalkali metals’ content are very low.X-ray powder diffraction analysis results show that the Sangpiyu anastomosistremolite nephrite jade standard diffraction data, the diffraction peak is sharp, thesymmetry is better, that higher crystallinity; Infrared spectrum analysis shows goodconsistency with standard tremolite spectra, high purity, Si4O11vibration absorptionpeak area is obvious. Laser Raman spectrum analysis of Si-O vibration is appointedin detail, Raman spectra of samples with different colors. Main impurity elements inthe form of class with quality like to enter, and causes the structure distortion, lead todifferences in spectral peak position and intensity.There are small differences inmineral composition and microstructure between Sangpiyu nephrite and otherproducting areas. The content of Fe, alkali metal elements and impurity ions are low.