Three tourmaline reference materials sourced from the Harvard Mineralogical and Geological Museum (schorl 112566, dravite 108796 and elbaite 98144), which are already widely used for the calibration of in situ boron isotope measurements, are characterised here for their oxygen and lithium isotope compositions. Homogeneity tests by secondary ion mass spectrometry (SIMS) showed that at sub‐nanogram test portion masses, their ¹⁸O/¹⁶O and ⁷Li/⁶Li isotope ratios are constant within ± 0.27‰ and ± 2.2‰ (1s), respectively. The lithium mass fractions of the three materials vary over three orders of magnitude. SIMS homogeneity tests showed variations in ⁷Li/²⁸Si between 8% and 14% (1s), which provides a measure of the heterogeneity of the Li contents in these three materials. Here, we provide recommended values for δ¹⁸O, Δ’¹⁷O and δ⁷Li for the three Harvard tourmaline reference materials based on results from bulk mineral analyses from multiple, independent laboratories using laser‐ and stepwise fluorination gas mass spectrometry (for O), and solution multi‐collector inductively coupled plasma‐mass spectroscopy (for Li). These bulk data also allow us to assess the degree of inter‐laboratory bias that might be present in such data sets. This work also re‐evaluates the major element chemical composition of the materials by electron probe microanalysis and investigates these presence of a chemical matrix effect on SIMS instrumental mass fractionation with regard to δ¹⁸O determinations, which was found to be < 1.6‰ between these three materials. The final table presented here provides a summary of the isotope ratio values that we have determined for these three materials. Depending on their starting mass, either 128 or 512 splits have been produced of each material, assuring their availability for many years into the future.

中文翻译：

---

用于氧和锂同位素比组成原位分析的电气石参考材料

来自哈佛矿物学和地质博物馆的三种电气石参考材料（schorl 112566，dravit 108796和elbaite 98144）已被广泛用于就地硼同位素测量的校准，在此对它们的氧和锂同位素组成进行了表征。二次离子质谱（SIMS）的均质性测试表明，在亚纳米级测试部分质量下，它们的¹⁸ O / ¹⁶ O和⁷ Li / ⁶ Li同位素比率分别恒定在±0.27‰和±2.2‰（1 s）内。 。三种材料的锂质量分数在三个数量级上变化。SIMS均匀性测试显示⁷ Li /在8％和14％（1 s）之间的²⁸ Si ，可以衡量这三种材料中Li含量的异质性。在这里，我们提供推荐值δ ¹⁸ O，Δ” ¹⁷ O和δ ⁷Li是三种哈佛电气石参考材料的依据，这是基于多个独立实验室使用激光和逐步氟化气体质谱法（适用于O）以及溶液多收集器电感耦合等离子体质谱法（适用于Li）进行的批量矿物分析结果得出的。这些大量数据还使我们能够评估此类数据集中可能存在的实验室间偏差的程度。这项工作也重新评估的材料的用电子探针微量分析和研究了主要元件的化学组成这些存在的相对于上SIMS仪器质量分馏化学基质效应为δ ¹⁸O的测定，发现这三种材料之间的<1.6‰。此处提供的最终表格提供了我们为这三种材料确定的同位素比值的摘要。根据它们的起始质量，每种材料已经生产了128或512分裂，以确保它们在未来多年内都可以使用。