独山玉矿物学研究及质量评价标准建立.doc

独山玉矿物学研究及质量评价标准建立 【中文摘要】本文综合运用矿物学、岩石学、宝石学、矿床地质学、地球化学等理论与方法，对河南南阳独山玉的矿物组分、岩矿特性、宝石学特征及玉石工艺等进行了研究，综合独山玉的颜色、品种、完美程度、新老坑和块度质量，以及独山玉矿开采实际和独山玉市场消费趋势，制定独山玉质量综合评价标准。独山玉属硅酸盐多矿物岩类玉石，为蚀变斜长岩或黝帘石化斜长岩，呈隐晶质，颜色复杂，具多色相互浸染交错，细粒致密结构，块状构造，玻璃-油脂光泽，质地细腻，致密坚硬，摩氏硬度6.5-8，半透明-不透明。主要矿物为基性斜长石、黝帘石，其次为铬云母、透辉石、钠长石、绿帘石、阳起石及少量黑云母及电气石；微量矿物有榍石、金红石、铬铁矿、黄铁矿等；次生矿物有沸石、葡萄石、方解石、褐铁矿、绢云母、绿泥石等。由岩浆结晶分异形成的独山玉源岩斜长岩，经历后期动力变质作用和热液交代变质作用是独山玉形成的主要过程。独山玉质量评价原则为颜色、质地、完美程度、块度、稀少程度，评价标准主要是建立在对颜色包括亚种、完善程度、新坑与老坑、块度重量的评价标准之上的。就颜色而言，独山玉共分8大色系品种和24个亚种及10余个混合色、过渡色。由此得知，独山玉从玉种上讲是以白天蓝、满绿、芙蓉红、透水白等为优。; 【Abstract】In this ***, the mineral components, characteristics of rock and precious stones and characteristics of the craft of Dushan jade from Nanyang area of Henan province were studied by integrated use of the theory and in mineralogy, petrology and gemology, deposit geology, and geochemistry. Considering many features of Dushan jade, such as the color, variety, the degree of perfection, the new and old pit, the weight of block, mining and the consumption trends in market, the standard of uation the quality of Dushan jade was constituted.Dushan jade belonging to the silicate mineral rocks, is an altered-plagioclase or zoisite-altered plagioclase. It is mainly made up of 50-90 of basic plagioclase anorthite, 5-70 of zoisite,5-15 of chrome mica, 1-5 of albite,1-5 of epidote and 1 actinolite, and the biotite and tourmaline were less than 1.There are some trace minerals, such as sphene, rutile, chromite, pyrite, and so on. Besides, the jade also comprises several secondary minerals, such as zeolite, grapes and calcite, limonite, sericite and chlorite. The minerals are different according to the type of jade.The physics character of Dushan jade is glass-oil sheen and fine texture, compact and hard, the hardness of 6.5-8 and cryptocrystalline .and the jade has complex color, granule texture and massive structure.The Dushan jade is identified the color, granular structure, the degree of transparency and hardness, density and refractive index. It is distinguished the other similar jade greenstone, jadeite and others as high Al_2O_3, high calcium and high Sr.The source rock of Dushan jade is plagioclase which is ed in the process of crystallization and differentiation of magma. The ing process of Dushan jade is late dynamic metamorphism and hydrothermal metasomatism.The principles of quality uation of Dushan jade is the color, texture, perfect, blocks, the degree of scarcity, and the first three factors are the key conditions.The criteria of quality uation of Dushan jade are based on the color including subspecies.The color of Dushan Jade may be divided into eight categories and 24 sub- categories and more than 10 mixed color and transitional color. So there are main types of Dushan jade in core, such as white-blue, full-green, lotus-red and lily-white.The criteria of quality uation of Dushan jade must be also considered the factors including degree of perfection, from new or old pit, weight of block and so on.