中国首次发现的氟闪叶石矿物学特征  

The mineralogical characteristics of fluorlamprophyllite first discovered in China

作　　者：葛祥坤[1] 李婷[1] 范光[1] 邰宗尧 沈敢富[2] GE Xiang-kun;LI Ting;FAN Guang;TAI Zong-yao;SHEN Gan-fu(Beijing Research Institute of Uranium Geology,Bejing 100029,China;Chengdu Institute of Geology and Mineral Resources,Chengdu 610082,China)

机构地区：[1]核工业北京地质研究院,北京100029 [2]成都地质矿产研究所,四川成都610082

出　　处：《岩石矿物学杂志》2023年第4期568-576,共9页Acta Petrologica et Mineralogica

基　　金：国家自然科学青年基金项目(42002044);中核集团青年英才项目(CEQNYC2020-2)。

摘　　要：闪叶石族矿物是富含Sr、Na、Ca和Ba等的钛硅酸盐矿物的总称,迄今共有19个矿物种,其中的氟闪叶石矿物首次发现于巴西Serrote山碱性岩中。本文利用电子探针和X射线衍射仪等分析测试手段,从化学成分和晶体结构等方面对产出于中国辽宁赛马碱性岩体中的闪叶石族矿物进行了详细的矿物学特征研究,发现其中常呈柱状、针状和纤维状集合体产出的闪叶石的晶体化学式为(Sr_(1.00)Na_(1.00))_(Σ2.00)Ti_(2)(Na_(1.98)Sr_(_(0.33))Mn_(0.26)K_(0.12)Mg_(0.10)Ca_(0.09)Ba_(0.05))_(Σ2.93)(Ti_(0.69)Fe_(0.33)^(3+)Al_(0.02))_(Σ1.04)(Si_(3.80)O_(14))O_(2)(F_(1.16)OH_(0.84))_(Σ2.00),属于单斜晶系,空间群为C2/m,晶胞参数a=19.2719(8)Å,b=7.0779(3)Å,c=5.3882(2)Å,β=96.780(2)°,V=729.84(5)Å^(3),Z=2。上述矿物学特征均与巴西发现的新矿物氟闪叶石的矿物学特征一致,表明赛马碱性岩体产出的氟闪叶石堪称该矿物种在中国的首次发现。不仅如此,赛马碱性岩体也有闪叶石产出,而且,迄今已发现多个新矿物,寓示该岩体仍有良好的新矿物发现前景。Lamprophyllite group minerals are the general name of titanosilicate minerals rich in Sr,Na,Ca and Ba etc.So far,there are 19 mineral species,of which fluorlamprophyllite was found in the alkaline rocks of the Serrote Mountain in Brazi for the first time.In this paper,the mineralogical characteristics of the lamprophyllite group min⁃erals in the Saima alkaline rock pluton in Liaoning Province,China,have been studied in detail in terms of chemi⁃cal composition and crystal structure by means of electron probe micro⁃analysis and X⁃ray diffraction.The results show that the minerals occur mainly in columnar,acicular and fibrous aggregates,and the single crystals are in sheet and plate shape.The crystal chemical formula is(Sr_(1.00)Na_(1.00))_(Σ2.00)Ti_(2)(Na_(1.98)Sr_(0.33)Mn_(0.26)K_(0.12)Mg_(0.10)Ca_(0.09)Ba_(0.05))_(Σ2.93)(Ti_(0.69)Fe_(0.33)^(3+)Al_(0.02))_(Σ1.04)(Si_(3.80)O_(14))O_(2)(F_(1.16)OH_(0.84))_(Σ2.00).It belongs to monoclinic system,with the space group of C2/m.The unit⁃cell parameters are a=19.2719(8)Å,b=7.0779(3)Å,c=5.3882(2)Å,β=96.780(2)°,V=729.84(5)Å^(3),Z=2.The mineralogical characteristics mentioned above are consistent with those of fluorlamprophyllite which is a new mineral discovered in the alkaline rock of the Serrote Mountain in Brazil for the first time,and the fluor⁃lamprophyllite studied in this paper is the first discovered in China.At the same time,it is pointed out that the Sai⁃ma alkaline pluton also includes lamprophyllite,and it implies that there is still a good prospect for the discovery of new minerals in the pluton because of its special element combination and formation conditions.

关 键 词：闪叶石族 氟闪叶石 电子探针 X射线衍射仪 赛马碱性岩体 

分 类 号：P578.94[天文地球—矿物学]