涂氏磷钙石:一种磷酸盐高压相新矿物  

Tuite: A new high-pressure phosphate mineral

作　　者：谢先德[1] M.E. Minitti 陈鸣[1] 毛河光 王德强[1] 束今赋 费英伟 

机构地区：[1]中国科学院广州地球化学研究所,广东广州510640 [2]Geophysical Laboratory Carnegie Institution of Washington,USA

出　　处：《地球化学》2003年第6期566-568,共3页Geochimica

基　　金：国家自然科学基金(40272028);中国科学院知识创新工程项目(KJCX2-SW-N03)

摘　　要：在随州陨石冲击熔脉中发现了一种磷酸盐新矿物,它是白磷钙石的高压多形,经国际矿物协会新矿物和矿物命名委员会批准,定名为涂氏磷钙石(Tuite)。该矿物属三方晶系,空间群为R-3m,a=5.258(1)?,c=18.727(3)?。一轴晶,正光性,ε=1.706(3),ω=1.701(4)。化学式为(Ca2.51Mg0.29)2.80Na0.28(P1.01O4)2,简化式为Ca3(PO4)2。X射线粉晶衍射的强谱线有:2.628(100)、2.891(80)、1.945(47)、1.730(25)和1.567(22)。根据与其共生的其他高压相矿物形成的温压条件和人工合成实验的结果,推定涂氏磷钙石形成的压力为12～23GPa,温度为1400到2000℃。该新矿物以中国矿物岩石地球化学学会的创建人和首任会长涂光炽的姓氏命名。Tuite is a new phosphate mineral found in a shock melt vein of the Suizhou L6 chondrite. It is identified as a high pressure polymorph of whitlockite. This new mineral is trigonal, R 3m, a=5.258 ?, c=18.727 ?, uniaxial (+) with ε=1.706 and ω=1.701, ε-ω=0.005. Its empirical formula is (Ca2.51Mg0.29)2.80Na0.28(P1.01O4)2, and the simplified formula is Ca3(PO4)2. Stronger reflections on X ray powder diffraction pattern of tuite are: d=2.628 (100), 2.891 (80), 1.945 (47), 1.730 (25), and 1.567 (22). Tuite occurs in association with other high pressure minerals such as ringwoodite, majorite, NaAlSi3O8 hollandite, majorite pyrope solid solution. The p t condition for tuite formation is estimated to be 12～23 GPa and 1 400～2 000 ℃. This new mineral is named after Professor TU Guang zhi.

关 键 词：涂氏磷钙石 白磷钙石 磷酸盐新矿物 高压多形 

分 类 号：P578.922[天文地球—矿物学]