南平花岗伟晶岩中的羟磷铝锂石矿物学研究

A Study on Montebrasite in the Nanping Granitic Pegmatite

羟磷铝锂石是南平稀有金属花岗伟晶岩中的重要标型矿物，可分为原生和次生两大类，最主要的是前者，一般呈块体状，共生矿物主要有销长石，钾长石，锂辉石，铌钽矿物。本文详细讨论了南平羟磷铝锂石的化学成分、Ｘ射线粉晶衍射资料、红外光谱和差热分析结果。南平原生羟磷铝锂石的交代蚀变作用十分发育，按其先后顺序，交代蚀变矿物组合有：石英—叶钠长石、次生羟磷铝锂石、细晶销长石—石英—次生磷灰石、次生复杂磷酸盐矿物和绢云母。

The montebrasite is an important typomorphic mineral in the Nanping rare-metal granitic pegmatites, which can be grouped into original type and secondary type. Most of them are the montebrasites of the orginal type,which occurs as a massive structure. The main associated minerals include albite, potash-feldspar, spodumene, Nb-Ta minerals. The paper presents the analysis results of the naping montebrasite, such as the chemical composition, Xray powder diffraction data, IR spectrum and differential thermal curves. The metasomatic alteration of the Naping original montebrasite is very strong. From early to late stage, the major metasomatic-alteration mineral assemblages include the quartz-cleavelandite, the secondary montebrasite, the fine-crystalline albite-quartz-secondary apatite, the secondary corn-plex phosphate minerals and sericite.