Liu Yan, Shen Zhang-Wu, Deng Jun, Jiang Shao-Qing
State Key Laboratory of Geo-processes and Mineral Resources, China University of Geosciences, Beijing 100083, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2008 Jul;28(7):1506-9.
Trace elements determination of cassiterites from Furong ore field indicates that there is a certain amount of Fe, Mn and Ti elements in cassiterite. The mean of unit-cell parameters for cassiterite is 7.165 (nm3) by the method of XRD analysis and the unit-cell parameter which also indicates that the genetic type of the ore field belongs to cassiterite-sulfide type, is bigger than that of other genetic type. Four IR active vibration frequencies in cassiterite samples also suggest that the IR spectra of cassiterites from Furong ore field belongs to deformed spectra suggesting that the genetic type of cassiterite from Furong ore field is mainly of cassiteriate-sulfur type. The Raman frequency of A1g peak has typomorphic significance to study its genetic type. A1g is a characteristic peak of cassiterite and AO2 oxide of the same structure style. Impure elements of cassiterite remarkably affect its Raman frequency which will move to low frequency if the contents of Nb and Ta reach a certain amount. In Furong ore field, A1g frequency of casstiterite is about 632 cm(-1) which is bigger than other cassiterites of various genetic types and the implication and character of Raman spectra are consistent with the cell parameters and IR analysis of these samples. Combined with the study of chemical composition and crystal structure, the IR spectra and Raman spectra can mean a lot for the analysis of genetic type of the cassiterite.
芙蓉矿田锡石微量元素测定表明，锡石中含有一定量的铁、锰和钛元素。通过X射线衍射分析方法测得锡石晶胞参数平均值为7.165（nm³），该晶胞参数表明矿田成因类型属锡石 - 硫化物型，比其他成因类型的要大。锡石样品中的四个红外活性振动频率也表明，芙蓉矿田锡石的红外光谱属于变形光谱，这表明芙蓉矿田锡石的成因类型主要为锡石 - 硫化物型。A1g峰的拉曼频率对研究其成因类型具有标型意义。A1g是锡石以及相同结构类型的AO₂氧化物的特征峰。锡石中的杂质元素对其拉曼频率有显著影响，当铌和钽含量达到一定量时，拉曼频率会向低频移动。在芙蓉矿田，锡石的A1g频率约为632 cm⁻¹，比其他各种成因类型的锡石都要高，且拉曼光谱的含义和特征与这些样品的晶胞参数及红外分析结果一致。结合化学成分和晶体结构研究，红外光谱和拉曼光谱对锡石成因类型分析具有重要意义。
