Mineralogical Characteristic of Dushan Yu Similar

With the similar colour and surface characteristics to the precious stones such as jadeite and emeralds, Dushan Yu similar sample has been a new market emerging stone in China. This papers made detail mineralogical characteristics of composition and structure on the rough samples by using electronic probe, X-ray powder diffraction, Raman spectroscopy and other instruments. The result showed that Dushan Yu similar sample is composed by anorthite (An₁₀₀), uvarovite (Uvt_49.66Grs_36.04 Adr_13.58Prp_0.67Sps_0.06), diopsidite, sphene, chromite, zoisite, prehnite and thomsonite, et al. Through thin section observation, the sample showed mainly mortar texture. Based on the specification for nomenclature of metamorphic rocks, the sample were named as uvarovite-anorthite mortar rock. Combined with the specification for the gemological, the sample should be named as anorthitic jade. According to the composition paragenetic combination characteristics, combined with previous data, metallogenic stage of the samples contained magmatic stage, metamorphic stage and late hydrothermal transformation stage, and the formation of uvarovite depended on the Cr³⁺ hydrothermal originates from chromite.