川西微晶白云母的X射线粉晶衍射分析

川西微晶白云母是一种新型的非金属矿物资源,采用X射线粉晶衍射分析对川西微晶白云母的进行了深入研究,发现该矿床存在白云母-多硅白云母矿物组合。该矿物组合中的微晶白云母和多硅白云母结晶度高,多型为2M1,其含量分别为80%和20%左右;二者都属二八面体型白云母类矿物,但d060和b值偏大,微晶白云母的d060=0.1502 nm,b=0.9012 nm,多硅白云母的d060=0.1505 nm,b=0.9030 nm;微晶白云母矿铝含量较低、铁镁含量较高,其原因是白云母晶体铝氧八面体中的Al离子被Fe、Mg等离子所取代,这一矿物组合是通过矿物类质同象作用所形成一种多硅白云母系列矿物。

CHARACTERISTICS OF MICRO-CRYSTAL MUSCOVITE IN WEST SICHUAN, CHINA: AN X-RAY POWDER DIFFRACTION ANALYSIS

In order to provide the scientific basis for further study and development of the new style nonmetallic mineral resources,micro-crystal muscovite,in West Sichuan,China,X-ray powder diffraction analysis is used to monitor their mineralogy and petrology characteristics.It is found that there is a mineral association,micro-crystal muscovite and phengite,in this deposit.The mineral assemblage contains about 80% micro-crystal muscovite and about 20% phengite.Their crystallinity is very high and their polytype is 2M_1.Both of them are dioctahedral because the d_(060) and b of micro-crystal muscovite and phengite are 0.1502 nm,0.9012 nm and 0.1505 nm,0.9030 nm,respectively.For their d_(060) and b are larger than those of common muscovite,the reason why Fe~(2 ) Fe~(3 )and Mg~(2 ) are high in the ore is that Al~(3 ) in the octahedron is replaced by Fe~(2 ) Fe~(3 )and Mg~(2 ),and this is a phengite series mineral association formed through isomorphic replacement.