The Study On Mineralogical Characteristics And Cause Study Of Tremolite Jade From Panshi, Jilin, China

Mineralogical properties and cause study of tremolite jade from Panshi, Jilin Province. Comparisons of tremolite jade from different deposits were also studied,which included gemological properties, mineralogical composition, structure and type of deposit.Tremolite jade from Panshi, Jilin mainly has colors: light yellowish green, light greenish yellow, light green and white with light grey tone. The jade is sub-translucent to opaque, and presents waxy to greasy luster on the polished surface.Cracks are observed in the samples. Through the conventional gemological test to tremolite jade from Panshi, Jilin, the density ranges from 2.81 g/cm3 to 2.93g/cm3,Moh’s hardness ranges from 5.50 to 5.82, refractivity is range from 1.60 to 1.62, these indexes are lower than the indexes of tremolite from other deposit.Polarized microscopic observation reveals the main mineral composition is tremolite, and the secondary minerals are calcite, dolomite, diopside and talc. Observd under the polarized microscope, the textures of Panshi tremolite jade are panniform crystalloblastic, microscopic fiber crystalloblastic and microscopic radial structure.The main composition of wall rock is carbonate mineral, which has the structure of heterogranular, with chloritization on the edge. Observation with BSE reveals that tremolite contacts to calcite. Further observation with cathodoluminescence shows that tremolite, calcite, dololite contact to each other. Summarize the results and analysis of the tests to the structure, it could be concluded that these three minerals appeared with the order by dololite, calcite, tremolite.The composition of samples were investigated by EPMA, XRD and Infrared spectroscopy. The main composition of tremolite jade of Panshi is tremolite, with the main chemical composition CaO, MgO, Si O₂, minor contains FeO, Al₂O₃, Na₂O, K₂O,etc. Diopside, carbonate mineral, talc, chlorite were also found in the samples.According to these studies above, it can be deduced that Panshi tremolite jade deposit belongs to magmatic hydrothermal metasomatism deposit, which can be originated from contact of dolomitic marble and eesozoic-cenozoic granite acid.Comparison of tremolite jade between Panshi, Jilin and other deposits were accomplished, which can conclude that the jade from Panshi, Jilin has larger grain in structure, and has lower percentage of tremolite mineral comparatively, which result in the lower indexes of the gemological characteristic.