The Study Of Qinglong Jade And The Research Of Its Reserves

In this paper, a new jade called Qinglong jade, which got the nameaccording to its production area Qinglong county in Qinhuangdao city, isresearched autoptically. For Qinglong jade, firstly, its mineral constitution andstructure were investigated and then the geological forming process wasanalyzed;secondly, the gemological parameters were measured;thirdly, thereserves was estimated. At last, the economic future of Qinglong jade waspredicted.The mineral constitution and structure of Qinglong jade were obtainedaccording to the experimental results of Lithic Facies Analysis (LFA), X-rayFluorescence analysis (XRF) and X-ray diffraction Analysis (XRD). Qinglongjade is mainly constituted of calcite, serpentine and so on. Small amount ofdiopside and phlogopite are found in some samples. The main mineralconstituting the jade is serpentinized marble, and several samples are completelycomposed of serpentine. The crystalloblastic texture of jade is various in kind,and the dominating crystalloblastic texture is granular crystalloblastic textureand fibroblastic texture.Geological forming process of Qinglong jade was then analyzed in thearticle. Qinglong jade is a kind of skarn mineral formed under the effect ofcontact metasomatism. It is deposited in the contacted belt between theMesozoic Yanshan Period intermediate rock to acid rock mineral zone and theProterozoic era dolomite rock mineral zone. The main constitution ofintermediate rock to acid rock is prophyritic granite and granite-diorite. Themain constitution of dolomite rock is calcite and dolomite.The gemological parameters of Qinglong jade were also measured. ForQinglong jade, the main color is green;the luster is varied from waxy to vitreous;the transparency is from opaque to translucent;the Mohs hardness is 3-4;thedensity is 2.63-2.67 g/cm3, whose average density is 2.65 g/cm3;the infraredabsorption spectra is of both typical infrared absorption spectra of calcite andserpentine. As there is no corresponding standard on testing this kind of jade inGB/T16553-2003 (Gem-Testing), the mending of national standard is suggested.At last, the reserves was estimated and the economic future of Qinglongjade was predicted. According to field survey, the jade mineral area is estimatedto be 30-40 m in width and 146 m in depth. And there are 3 strips of jademineral depositing area, whose total length is 30000 m. The predicted reservesof Qinglong jade is about 9.92×107 t, which is far more than the standard oflarge-scale jade mineral 5×107 t. So the economic future of the jade isenormous.