翡翠的表生地球化学及其应用

THE EPIGENTIC GEOCHEMISTRY OF FEICUI AND ITS APPLICATION

缅甸翡翠是一种极少见的富Na贫Si的超基性岩，在高压低温下经受了不同程度的变质作用。一般情况下，翡翠都含少量Fe、Mn、Cr等致色元素，因此出现绿色、紫色、黄红色和黑色。在表生作用中，Fe2＋氧化形成翡和红雾，Mn2＋氧化成棕、黑色的物质，Cr3＋较易被淋失。翡翠皮壳的砂发、红雾、松花、蟒带、黑癣、猫尿等，是鉴别赌石的重要标志；在加工过程中红雾、猫尿常可被作为巧色加以利用，增加了翡翠的工艺价值和经济价值。

Burma feicui is a very rare ultrabasic rock rich in Na and poor in Si, morn or less meta morphosed under high P and low T conditions Generally, there are a little Fe, Mn and Cr,etc color elements in feicui so that it is green, purple,, yellow-red and black. In epigenesis,the Fe2+oxidation forms green and red fog, Mn2+oxidation forms brown, black materials,Cr3+ is easily leached out. Various color materials on the feicui crust are important indications for gamble stone identification. And in processing, some of them can be applied to increasing the art and economic values of feicui