In nature a wide variety of minerals are known with the general formula X2M(TO4)2·2(H2O) and an important group is formed by minerals with T = As. Most of these occur as minor or trace minerals in environments such as hydrothermal alterations of primary sulfides and arsenides. X-ray Photoelectron Spectroscopy (XPS) and Raman microspectroscopy have been utilized to study the chemistry and crystal structure of the roselite subgroup minerals, Ca2M(AsO4)2·2H2O (with M = Co, Mg, Mn, Zn, and Cu). The arsenate AsO4 stretching region exhibited minor differences between the roselite subgroup minerals, which can be explained by the ionic radius of the cation substituting on the M position in the structure. Multiple AsO4 antisymmetric stretching vibrations were found, pointing to a tetrahedral symmetry reduction. Similar observations were made for the corresponding bending modes. Bands around 450 cm-1 were attributed to ν4 bending modes. Several bands in the 300â350cm-1 region attributed to ν2 bending modes also provide evidence of symmetry reduction of the AsO4 anion. Two broad bands for roselite were found around 3330 and 3120 cm-1 and were attributed to the OH stretching bands of crystal water. These bands are accompanied by two bands around 1700 and 1610 cm-1 attributed to the corresponding OH-bending modes. In conclusion, both XPS and Raman spectroscopy have been shown here to be valuable non-destructive analytical tools to characterize these secondary arsenate minerals. X-ray Photoelectron Spectroscopy and Raman microspectroscopy allow the chemistry and molecular structure of the roselite subgroup minerals to be studied in a non-destructive way. The minerals in the roselite subgroup are easily distinguished based on their chemical composition as determined by XPS. As expected for minerals with the same crystal structure, similarities exist in the Raman spectra, sufficient differences exist to be able to identify these minerals.

中文翻译：

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EXPRESS：系统拉曼光谱研究砷酸盐矿物玫瑰红石、温德威尔森石、锌铬铁矿、白兰地石和红镁石之间的同构性。

在自然界中，已知有多种矿物，其通式为 X2M(TO4)2·2(H2O)，其中一个重要的组是 T = As 的矿物。其中大部分在环境中以微量或微量矿物质形式出现，例如原生硫化物和砷化物的热液蚀变。X 射线光电子能谱 (XPS) 和拉曼显微光谱已被用于研究玫瑰色亚群矿物 Ca2M(AsO4)2·2H2O（M = Co、Mg、Mn、Zn 和 Cu）的化学和晶体结构。砷酸盐 AsO4 拉伸区域在玫瑰色亚族矿物之间表现出微小的差异，这可以通过取代结构中 M 位置的阳离子的离子半径来解释。发现了多个 AsO4 反对称伸缩振动，表明四面体对称性减少。对相应的弯曲模式进行了类似的观察。450 cm-1 左右的波段归因于 λ4 弯曲模式。在 300–350cm-1 区域归因于 Δ2 弯曲模式的几个波段也提供了 AsO4 阴离子对称性减少的证据。在 3330 和 3120 cm-1 附近发现了玫瑰花的两条宽谱带，这归因于结晶水的 OH 伸缩带。这些带伴随着 1700 和 1610 cm-1 附近的两个带，归因于相应的 OH 弯曲模式。总而言之，XPS 和拉曼光谱在这里已被证明是表征这些次生砷酸盐矿物的有价值的非破坏性分析工具。X 射线光电子能谱和拉曼显微光谱允许以非破坏性方式研究玫瑰色亚群矿物的化学和分子结构。根据 XPS 确定的化学成分，玫瑰石亚群中的矿物很容易区分。正如对具有相同晶体结构的矿物所预期的那样，拉曼光谱中存在相似性，存在足够的差异以能够识别这些矿物。