一、引言铬铁矿是我国急需矿种之一,我所地质科技人员自建所以来,在陕、甘、宁、青、新等地区对铬铁矿的物质成分与成矿规律作了研究工作,随着地质科研的深入,对铬尖晶石类质同象系列正确定名的要求也越来越迫切,能否通过X射线粉晶鉴定来解决这个问题,成了大家关心的课题。近十年来,我们收集了楼房沟、松树沟、绿梁山、金川、大道尔吉、萨尔托海等地的铬尖晶石类矿物X射线粉晶分析数据,通过与91个有化学分析资料的铬尖晶石进行对比、统计及数据处理,初步获得晶胞大小与矿物物质成分的关系,可以按晶胞值的大小,大致划分六种铬尖晶石类矿物。同时推导了铬尖晶石晶胞值的近似经验计算公式,从而对铬尖晶石巴甫洛夫分类与晶胞大小关系的规律有了进一步 I. INTRODUCTION Chromite is one of the most urgently needed minerals in our country. Since the geoscience and technical personnel of our institute built on their own, we have studied the material composition and metallogenic regularity of chromite in the regions of Shaanxi, Gansu, Ningxia, Qinghai and New China Work, with the deepening of geological research, the right to name the same type of chromium spinel isomorphic series of more and more urgent requirements, whether through X-ray powder crystal identification to solve this problem, has become the subject of concern. In the past ten years, we have collected the data of X-ray powder analysis of chromium spinel minerals in the buildings of Fufanggou, Songshugou, Luliangshan, Jinchuan, Daerji Erzi, Salto Sea and so on. By comparing with the data of 91 chemical analysis materials Chromium spinel comparison, statistics and data processing, the initial access to the relationship between unit cell size and mineral composition, the unit cell size can be roughly divided into six kinds of chromium spinel minerals. At the same time, we derive the approximate empirical formula for calculating the spinel cell number of chromium spinel so as to further study the relationship between the chrome spinel Pavlov classification and unit cell size