马达加斯加草莓红绿柱石的成因与产状特征  

Formation and Occurrence of Pezzottaite from Madagascar

作　　者：廖尚宜[1] 彭明生[1] 李勋贵[1] 

机构地区：[1]中山大学宝石矿物材料研究所,广州510275

出　　处：《矿物岩石地球化学通报》2006年第2期133-136,共4页Bulletin of Mineralogy, Petrology and Geochemistry

摘　　要：对马达加斯加新发现的宝石矿物草莓红绿柱石矿床的地质考察和研究发现,矿体属典型的复杂的锂-铯-钽型稀有金属晶洞花岗伟晶岩.出露于花岗岩的上部,沿片麻岩理呈脉状产出,宽十余米,产状170°～180°∠45°～55°.交代作用明显,带状构造发育,由矿体边缘至中心部位可分为6个带.草莓红绿柱石主要分布于石英-微斜长石带至石英核内,为伟晶岩晚期形成的矿物,与锂云母、叶钠长石、多色电气石、锂辉石和烟水晶等伴生.矿化富集与钾钠长石化、锂云母化直接有关.晶体,多呈不规则块状、六方板柱状或螺柱状;是由晚期富Li-Cs的热液交代变质而成.The authors have visited the pegmatite mine, with a newly discovered gem mineral - Pezzottaite, in Madagascar and have learnt about its geology. The pezzttaite occurred in a complex type （LCT） rare element miarolitic granitic pegmatite. The pegrnatite occurred as dikes within mica schists interbedded with impure marbles above the granite. The pegmatite dikes are generally about 10-13m thick, with dipping orientation of 170°-180° and dipping angles of 45°-55° （170°～180°∠45°～55°）. There is obvious metasomatism in rocks with banded.structure. From the edge to the core of the pegmatite dike, 6 zones were divided. The pezzottaite, formed in late-stage of pegmatite, is mainly distributed in the zones between the massive-quartz-microcline zone and the quartz core. It intergtown with lepidolite, clevelandite, multicolored tourmaline, spodumene and smoky quartz. It is closely associated with the K-feldsparization, alhitization and muscovitization of lepidolite. Most of the pezzottaite crystals are in irregular, hexagonal tabular or screw forms. It is believed that the pezzottaite was formed through the process of metasomatism by Li-Cs rich fluids.

关 键 词：草莓红绿柱石 稀有金属晶洞花岗伟晶岩矿床 马达加斯加 

分 类 号：P619.281[天文地球—矿床学]