云南永善金沙矿区砷硫锑铅矿的发现

The discovery of geocronite in the Jinsha mining district, Yongshan, Yunnan

砷硫锑铅矿产于金沙矿区的上部矿中。与闪锌矿一起构成矿石的主要金属矿物。含矿围岩为硅质磷块岩。矿床属沉积（成岩）成因。砷硫锑铅矿呈灰色，具金属光泽，为板状晶体；单偏光下为灰色或灰白色微带浅绿色，反射率较高；以具清晰的非均质性为特征。电子探针成分分析，主...

Abstract Geocronite has been found to occur in the upper ore horizons of the Jinsha mining district as the essential metallic minerals in the ores together with sphalerite. The ore bearing wall rocks are composed mainly of siliceous phosphorites.The ores are of sedimentary(diagenetic)origin.Geocronite is characterized by grey colour,metallic luster and tabular crystals,and grey or greyish white colour with slightly light green colour in the planepolarized light,higher reflectance and distinct anisotropism.The electron microprobe analyses have revealed that the contents of the major elements are:S=17 12%～17 92%,Pb=66.89%～70 79%,As=4 75%～7 27%,Sb=2 41%～8 22%.The caiculated atom numbers are:S=8 03～9 42,Pb=4 80～5 37,As=0 72～1 66,Sb=0 34～1 26.The chemical formula of geocronite is Pb 4 80～5 37 (As 0 72～1 66 Sb 0 34～1 26 ) 2S 8 03～9 42 .