河南省南阳独山玉东矿带地质特征

Geological characteristics of east ore belt of Dushan jade mine in Nanyang,Henan Province

独山玉是我国史书记载的四大名玉之一,因其色彩缤纷,玉质坚硬,其工艺品玲珑剔透,俏色天成,深受世人喜爱。独山玉矿体的地质特征、矿物组合、化学成份较为特殊。玉矿体赋存于辉长岩体中,矿体规模小,属于分布不均匀却又成群出现的小脉状矿体,常形成玉脉密集带。独山玉矿物成分以基性斜长石、黝帘石为主,含有铬云母、透辉石、钠长石、绿帘石、阳起石、黑云母等,矿物成分决定了玉石的颜色。玉矿石属SiO2弱饱和弱碱性的中色岩石,玉石中TiO2、Cr2O3含量与玉石颜色相关。本文在分析独山玉地质特征、矿床成因、找矿标志及开发利用的基础上,认为独山玉资源潜力较大,玉石加工性能好,具有良好开发利用前景。

Dushan jade from Nanyang is one of the four famous jades recorded in the ＂History Book＂ of our country. Dushan jade has splendid colours and fine-grained and delicate textures. Dushan jade sculptures are exquisitely carved and full of natural pretty colours and thus very likable for consumers. Dushan jade ore bodies are quite special in geological feature, mineral association and chemical composition. The jade ore bodies are occurred in a gabbroic pluton and the scale of ore bodies is rather small ,being unequally distributed but clustered to form a series of zones of concentrated small jade veins. The mineral composition of the jade is mainly consisted of plagioclase and zoisite,containing fuchsite, diopside, albite, epidote,actinolite, biotite etc. The mineral composition of the jade decides the colours of jade. The jade belongs to SiO2 weak-saturated and weak-alkaline mesocrate. The colours of the jade are related to TiO2 and Cr2O3 contents. Analyzing the geological characteristics, genesis and ore-hunting indicator of the jade deposit ,this paper considers that the potentiality of the jade resources is great ,the processing property of the jade is good and therefore Dushan jade deposit has a fine prospect for exploitation and utilization.