闪锌矿中的Cd主要类质同象置换Fe而不是Zn  

Cd Primarily Isomorphously Replaces Fe but not Zn in Sphalerite

作　　者：刘铁庚[1] 叶霖[1] 周家喜[1] 王兴理[1] 

机构地区：[1]中国科学院地球化学研究所矿床地球化学国家重点实验室,贵州贵阳550002

出　　处：《矿物学报》2010年第2期179-184,共6页Acta Mineralogica Sinica

基　　金：国家973项目(编号2009CB421003);中国科学院知识创新工程重要方向项目(编号:KZCX2-YW-111-03)

摘　　要：闪锌矿是自然界广泛分布的金属矿物,经常含微量的Fe、Cd等杂质元素,并认为Cd和Fe以类质同象方式取代了Zn。但是作者注意到,闪锌矿中的Cd与Zn基本都呈正相关关系,而与Fe呈很好的负相关关系。依照类质同象的定义,类质同象替换的二个元素应该呈负相关关系。因此,我们认为闪锌矿中的Cd主要不是类质同象替换Zn,而是取代了Fe。闪锌矿中的铁主要是Fe2+。Fe2+与Cd2+地球化学性质相似,FeS与CdS的键长和晶格能相近,因此,Cd完全可以类质同象置换闪锌矿中的Fe2+。The sphalerite is a kind of metal mineral that extensively occur in nature.It often contains trace Cd and Fe etc.People generally think that Cd isomorphously replaces Zn in sphalerite.But we discovered that the relation of content of Zn and Cd in sphalerite is positive,and that of Cd and Fe is negative.According to the theory of isomorphism,replace elements must be in the negative correlation.Thus we think that Cd dose not isomorphously replace Zn but Fe in sphalerite.Iron is in the form of Fe^2＋ in sphalerite.Both parameters and characteristics of Cd2＋ are similar with Fe^2＋.The energy of Crystal lattice of CdS is also similar with FeS.Therefore,we think that Cd can isomorphously replace Fe^2＋ in sphalerite.

关 键 词：闪锌矿 类质同象 锌 镉 铁 

分 类 号：P574.2[天文地球—矿物学] P578.2[天文地球—地质学]