The present work reports the crystal-chemical characterization of micas from the Monte Arsiccio and Buca della Vena mines (Apuan Alps, Italy) through electron microprobe analysis, single-crystal X-ray diffraction, and Raman spectroscopy. The sample from the Monte Arsiccio mine can be classified as an intermediate member of the yangzhumingite-fluorophlogopite series, with average crystal-chemical formula (K0.85Na0.01Ba0.09)Σ=0.95(Mg2.11Fe2+0.23Fe3+0.11Cr3+0.01Al0.20Ti0.04☐0.30)Σ=3.00(Si3.20Al0.80)Σ=4.00O10.00F1.90Cl0.02(OH)0.08. Unit-cell parameters are a ~ 5.30, b ~ 9.18, c ~ 10.14 Å, β ~ 100.12°, V ~ 486.22 Å3, corresponding to the 1M polytype. Structure refinements, performed in C2/m space group, converged to R1 = 3.54 and 4.46% and provided Mg plus Fe occupancy in the range 86–94% for the octahedral M1 and M2 sites. Raman spectroscopy shows very weak bands in the OH stretching region at ~ 3690 and 3580 cm−1. The sample from the Buca della Vena mine has been identified as an (OH)-rich fluorophlogopite, with average crystal-chemical formula (K0.84Na0.02Ca0.01)Σ=0.87(Mg2.12Fe2+0.55Fe3+0.10Al0.18☐0.05)Σ=3.00(Si2.99Al1.01)Σ=4.00O10.00F1.02Cl0.09(OH)0.89. Its unit-cell parameters are a ~ 5.33, b ~ 9.22, c ~ 10.23 Å, β ~ 100.09°, V ~ 494.39 Å3. Structure refinements gave good R1 values (3.27 and 4.37%) and revealed octahedral occupancy of 82–84% Mg and 16–18% Fe. Strong Raman signals at ~ 3702 cm−1 and 3595 cm−1 were observed in the OH stretching region. The findings allow to better understand not only the mineralogy of the Apuan Alps but, more generally, the crystal chemical details of intermediate dioctahedral-trioctahedral mica belonging to the yanzhumingite-fluorophlogopite series.

中文翻译：

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来自阿普安阿尔卑斯山（意大利托斯卡纳北部）扬珠明岩-氟金云母和金云母-氟金云母系列云母的晶体化学

目前的工作通过电子探针分析、单晶 X 射线衍射和拉曼光谱报告了来自 Monte Arsiccio 和 Buca della Vena 矿（意大利阿普安阿尔卑斯山）的云母的晶体化学特征。Monte Arsiccio矿样品可归类为扬珠明矿-氟金云母系列的中间成员，平均晶体化学式(K0.85Na0.01Ba0.09)Σ=0.95(Mg2.11Fe2+0.23Fe3+0.11Cr3+ 0.01Al0.20Ti0.04☐0.30)Σ=3.00(Si3.20Al0.80)Σ=4.00O10.00F1.90Cl0.02(OH)0.08。晶胞参数为 a ~ 5.30、b ~ 9.18、c ~ 10.14 Å、β ~ 100.12°、V ~ 486.22 Å3，对应于 1M 多型。在 C2/m 空间群中进行的结构改进收敛到 R1 = 3.54 和 4.46%，并为八面体 M1 和 M2 位点提供了 86-94% 的 Mg 和 Fe 占有率。拉曼光谱在~3690 和 3580 cm-1 处的 OH 拉伸区域显示非常弱的谱带。来自 Buca della Vena 矿的样品已被鉴定为富含 (OH) 的氟金云母，平均晶体化学式 (K0.84Na0.02Ca0.01)Σ=0.87(Mg2.12Fe2+0.55Fe3+0.10Al0.18 ☐0.05)Σ=3.00(Si2.99Al1.01)Σ=4.00O10.00F1.02Cl0.09(OH)0.89。其晶胞参数为 a ~ 5.33, b ~ 9.22, c ~ 10.23 Å, β ~ 100.09°, V ~ 494.39 Å3。结构改进给出了良好的 R1 值（3.27 和 4.37%），并揭示了 82-84% Mg 和 16-18% Fe 的八面体占有率。在 OH 拉伸区域观察到~3702 cm-1 和 3595 cm-1 处的强拉曼信号。这些发现不仅可以更好地了解阿普安阿尔卑斯山的矿物学，而且可以更广泛地了解