New Compositional and Structural Constraints on the Smithsonian Microanalytical Reference Materials: Amphiboles from Kakanui and Arenal
New Compositional and Structural Constraints on the Smithsonian Microanalytical Reference Materials: Amphiboles from Kakanui and Arenal
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DOI：
10.1111/ggr.12486
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发表时间：
2023-02
影响因子：
3.8
通讯作者：
Yujie Liu;Wenqiang Yang;C. Zhang;Zhian Bao;Shitou Wu;R. Almeev;F. Ridolfi;R. Oberti
中科院分区：
文献类型：
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作者：
Yujie Liu;Wenqiang Yang;C. Zhang;Zhian Bao;Shitou Wu;R. Almeev;F. Ridolfi;R. Oberti
Kakanui和Arenal的角石是两种天然矿物，在世界范围内被用作微量分析标准物质，但它们的组成和晶体结构仍然很少受到限制。在本文中，我们报道了这两种角闪石的水和微量元素质量分数和单晶结构细化的新数据。Karl - Fischer滴定法测定Kakanui角闪石和Arenal角闪石的水质量分数分别为0.92±0.18 （2s）和1.56±0.22% m/m (2s)；这些基于晶体结构精细化估计的值分别为0.86和1.46% m/m。两个实验室通过LA - ICP - MS测量的微量元素质量分数非常一致，Kakanui和Arenal角闪石的5个片段的点在可重复性精度（2s）内基本一致。我们的测量表明，Kakanui角闪石的均匀性优于Arenal角闪石。根据最新的角闪洞分类和命名方案（Hawthorne et al. 2012），来自Arenal的样品是一种（部分脱氢的）羽衣虫，而来自Kakanui的样品是一种角闪石。两种角闪石在M(1)位点的氧组分的显著含量和CTi4+含量的强烈有序表明在高fO2条件下结晶。
The amphiboles from Kakanui and Arenal are two natural minerals that have been used worldwide as microanalytical reference materials, but their compositions and crystal structures are still poorly constrained. In this paper, we report new data on H2O and trace element mass fractions and single‐crystal structural refinement of these two amphiboles. H2O mass fractions of the Kakanui and Arenal amphiboles determined via Karl‐Fischer titration are 0.92 ± 0.18 (2s) and 1.56 ± 0.22% m/m (2s), respectively; these values estimated based on crystal‐structure refinement are 0.86 and 1.46% m/m, respectively. Trace element mass fractions measured via LA‐ICP‐MS in two laboratories are in good agreement, and spots from five fragments for both Kakanui and Arenal amphiboles are generally consistent within reproducibility precision (2s). Our measurements indicate a better homogeneity for the amphiboles from Kakanui than that from Arenal. According to the latest scheme for amphibole classification and nomenclature (Hawthorne et al. 2012), the sample from Arenal is a (partially dehydrogenated) pargasite, and that from Kakanui is a kaersutite. The significant amount of oxo‐component and that CTi4+ content is strongly ordered at the M(1) site for both amphiboles indicate crystallisation under high fO2 conditions.