浙江遂昌某金矿床蔷薇辉石的研究

On the Study of the Rhodonite from a Certain Gold Deposit in Suichang,Zhejiang

蔷薇辉石Mn[SiO_(3)]可在不同锰矿床中见到。它在自然界可以作为热液作用和接触变质作用的产物,也可由沉积锰矿石经区域变质作用形成[1、2]。蔷薇辉石产于金矿床中则具有特殊的重要意义。

The mineralogical study of the rhodonite from a certain gold deposit located in Suichang of Zhejiang province,China,including the chemical composition,crystal structure and physical properties of rhodonite,is relevant to the genesis information on the deposit type and the conditions of its genesis,and is of typomorphic significance.The systematic data,which include the general geology of the gold deposit,the chemical composition(the main composition).crystal structure(diffraction of X-ray and unit cell extent),and some physical properties(such as refractive index,reflectance,microhardness,specific gravity,differential thermal analysis,thermal luminescence and infrared spectra)of the rhodonite,are given in this paper.The problems of the typomor-phic peculiarities of rhodonite and the genesis of a certain gold deposit in Suichang are discussed.On basis of the mineralogical study,the author holds that the typomorphic peculiarities of the rhodonite would be of some help to the research into the"subvolcanic rocks"genesis of the gold deposit.As a result of the study of mineralogy of rhodonite,it has provided mineralogical marks for surveying and prospecting of volcanic hydrothermal gold deposits.These mineralogical marks indicate the following typomorphic peculiarities of rhodonite.Rhodonite from a certain gold deposit in Suichang,Zhejiang has the chemical formula(Mn_(4.080)Ca_(0.330)Mg_(0.127)Fe_(0.019))_(4.556)Si_(5.222)O_(15.000),Lattice unit cell extent a:b:c=0.627:1:0.572.Refractive index Ng is 1.7395+0.0065,Nm is 1.7280+0.0050 and Np isl.7210+0.0010.Reflectance R546=0.076+0.001.Microhardness Hv is 489.5+30.5kg/mm^(2).Specific gravity D=3.675+0.055.DTA curve has a endothermal valley near 1214℃ or 1114℃ and a small valley in the vicinity of 1189℃ or 1165℃ New mineralogical marks for surveying and prospecting of volcanic hydrothermal gold deposits are thermal luminescence and infrared spectra of rhodonite,Gold bearing rhodonite has strong thermal luminescence and the thermoluminescence curve has a distinct peak.The major infrared spectra absorbefficient peaks move 2-11 cm^(-1) toward the short wave direction.