於祖相石,Sr_(3)Fe^(3+)(Si_(2)O_(6))_(2)(OH)·3H_(2)O:一种链状硅酸盐新矿物  

Yuzuxiangite,Sr_(3)Fe^(3+)(Si_(2)O_(6))_(2)(OH)·3H_(2)O:a new inosilicate mineral

作　　者：谷湘平 杨和雄[2] 谢先德 刘光华[1] GU Xiangping;YANG Hexiong;XIE Xiande;LIU Guanghua(Guanghua School of Gemmology and Mineral Resources,Jiangxi University of Applied Science and Technology,Nanchang Jiangxi 330100,China;Department of Geosciences,University of Arizona,1040 E.4th Street,Tucson,AZ 85721-0077,USA;Key Laboratory of Mineralogy and Metallogeny,Guangzhou Institute of Geochemistry,CAS,and Guangdong Key Laboratory of Mineral Physics and Materials,Guangzhou Guangdong 510640,China;School of Geosciences and Info-Physics,Central South University,Changsha Hunan 410083,China)

机构地区：[1]江西应用科技学院宝石与矿物资源学院,江西南昌330100 [2]亚利桑那大学地球科学系,美国图森市第4街1040号,邮编AZ 85721-0077 [3]中国科学院地球化学研究所矿物学与成矿学重点实验室/广东省矿物物理与材料重点实验室,广东广州510640 [4]中南大学地球科学与信息物理学院,湖南长沙410083

出　　处：《矿物学报》2024年第5期630-642,共13页Acta Mineralogica Sinica

基　　金：国家自然科学基金资助(批准号:41172042、42072054)。

摘　　要：於祖相石发现于南非北开普省卡拉哈里锰矿田韦瑟尔锰矿,呈浅棕色微晶-纳米纤维状集合体产出,集合体粒度50~200μm,共生矿物有硅镁锶钠石(meieranite)、羟钾锶鱼眼石[hydroxymcglassonite-(K)]、钠锂大隅石(sugilite)、针钠钙石(pectolite)、霓石等,呈玻璃光泽,具平行(100)及(001)的完全解理,估测莫氏硬度3–3½,计算密度3.451 g·cm^(-3)。在光学显微镜下,於祖相石为无色-浅黄色的针状、纤维状晶体,单晶体粒径<3μm,二轴晶负光性,α=1.66(3),β=1.68(5),γ=1.72(3)(白光),2Vcal=72°。其拉曼光谱出现100~1500 cm^(-1)范围里22个拉曼位移峰,归属Si—O,Fe—O,Sr—O振动模式,1500~4000 cm^(-1)范围里出现5个拉曼位移峰,归属OH,H2O的振动模式。其经验化学式为(Sr2.94Pb0.04Ca0.02)Σ3(Fe0.91Al0.09)Σ1[(Si3.98 Al0.02)Σ4O12](OH)·3H2O,理想式Sr_(3)Fe(Si_(2)O_(6))_(2)(OH)·3H2O。X射线单晶衍射结构分析确定於祖相石为单斜晶系,空间群P21/m,晶胞参数a=11.1035(10)Å,b=7.8463(7)Å,c=7.8222(7)Å,β=101.406(8)°,V=668.02(11)Å3,Z=2。於祖相石与水硅钛锶石(ohmilite)等结构,由2条平行的SiO4四面体单链(2T4p)夹FeO4(OH)2八面体链形成平行b轴的复合链,链间空隙分布Sr2+和H2O分子。其X射线粉晶衍射最强线条为:dÅ(I%,hkl):4.632(92,111),3.486(100,021),3.291(67,021),3.065(57,–221),2.841(48,311),2.118(49,330),1.956(46,040)。於祖相石的命名以致敬和纪念矿物学家於祖相教授(1930—2019)的学术贡献。Yuzuxiangite was discovered in the Wessels Mine,Kalahari Mangnese Field,North Cape Province of Africa.It occurs as agglomerates of acicular and fiberous crystals,50-200μm in size of the aggregate,in association with meieranite,hydroxymcglassonite-(K),sugilite,pectolite and aegirine.It has light brown color,vitreous lustre,perfect cleavages parallel to(100)and(001),an estimated Mohs hardness of 3-3½,and the calculated desity of 3.451 g·cm^(-3).Under microscope of transmittance light,yuzuxiangite is observed as colorless to light yellow acicular and fiberous crystals with single crystal size less than 3μm in diameter.It is biaxial crystal(-),α=1.66(3),β=1.68(5),γ=1.72(3)(white),2Vcal=72°.Its Raman spectrum consists of 22 peaks in 100-1500 cm^(-1),belonging to the Si-O,Fe-O,and Sr-O vibration modes,and 5 peaks in 1500-4000 cm^(-1)belonging to OH and H2O vibration modes.Its ideal formula is Sr_(3)Fe(Si_(2)O_(6))_(2)(OH)3H2O and its empirical formula(based on cation=8)is(Sr2.94Pb0.04Ca0.02)Σ3(Fe0.91Al0.09)Σ1[(Si3.98 Al0.02)Σ4O12](OH)3H2O.The X-ray single crystal diffraction analysis confirms that uzuxiangite belongs to the monocliniccrystal system,with cell paramters of space group P21/m,a=11.1035(10)Å,b=7.8463(7)Å,c=7.8222(7)Å,β=101.406(8)°,V=668.02(11)Å3,Z=2.The crystal structure of yuzuxiangite is same with ohmiite,characterized by a composite chain parallel to the b-axis,composed of a chain of cornershared FeO4(OH)2 octahedra flanked by 2 parallel chains(2 T4p)of corner-shared SiO4 tetrahedra,leaving the surrounding space occupied by Sr and H2O.The strongest powder X-ray diffraction lines are of dÅ(I%,hkl),including 4.632(92,111),3.486(100,021),3.291(67,021),3.065(57,-221),2.841(48,311),2.118(49,330),and 1.956(46,040).Yuzuxiangite is named in honor of Prof.YU Zuxiang(1930-2019),an eminent Chinese mineralogist with important contributions to studies of new minerals,especially to studies of platinum-group element minerals in China.

关 键 词：於祖相石 水硅钛锶石 新矿物 链状硅酸盐 卡拉哈里锰矿田 南非 

分 类 号：P57[天文地球—矿物学]