Zircon <scp>S513</scp> – A New Gem‐Quality Reference Material for <i>In Situ</i> Microbeam U‐Th‐Pb, (U‐Th)/He Geochronology and Hf‐O Isotope Measurement

A new gem‐quality zircon reference material, S513, was developed for in situ microbeam U‐Th‐Pb, (U‐Th)/He geochronology and Hf‐O isotope measurement. The well‐cut gem‐quality zircon weighed 51.3 carats. Its U, Th, Pb and Hf mass fractions were 924 ± 64.6 μg g −1 (2 s ), 89.6 ± 3.92 μg g −1 (2 s ), 119 ± 5.20 μg g −1 (2 s ) and 8259 ± 244 μg g −1 (2 s ), respectively. Imaging results from LA‐ICP‐ToF‐MS analysis showed homogeneous distribution of elements in S513. The Th‐corrected weighted mean 206 Pb/ 238 U, 207 Pb/ 235 U and 207 Pb/ 206 Pb ratios of S513 zircon from eight ID‐TIMS analyses are 0.090955 ± 0.000019 (2 s , MSWD = 0.22, n = 8), 0.73873 ± 0.00023 (2 s , MSWD = 0.19, n = 8) and 0.058934 ± 0.000008 (2 s , MSWD = 0.35, n = 8), respectively. The Th‐corrected weighted mean 206 Pb/ 238 U age obtained from chemical abrasion‐isotope dilution‐thermal ionisation mass spectrometry is 561.18 ± 0.63 Ma ( n = 8, 95% conf., MSWD = 0.9), which is recommended as the best age estimate of S513. The weighted mean 206 Pb/ 238 U ages obtained from in situ microbeam analysis (i.e., LA‐ICP‐MS and SIMS) were 560.8 ± 5.8/10.2 Ma (2 s , n = 260) and 562.4 ± 7.2/13.4 Ma (2 s , n = 198). The measured weighted mean 208 Pb/ 232 Th age of S513 from LA analyses was 561.3 ± 3.3/11.7 Ma (2 s , n = 86). The U‐Pb and Th‐Pb ages of S513 obtained with in situ methods showed good agreement with the CA‐ID‐TIMS results, respectively. The obtained (U‐Th)/He age of S513 from thirty‐seven aliquots analysed with U‐Th isotope dilution method was 420.3 ± 7.6 Ma (2 s , MSWD = 0.72). The recommended reference value of Hf isotope ratio was 0.281606 ± 0.000010 (2 s , MSWD = 1.4, n = 12) according to the mean 176 Hf/ 177 Hf ratio acquired with solution MC‐ICP‐MS analysis. All the LA analyses yielded a mean 176 Hf/ 177 Hf ratio of 0.281605 ± 0.000008 (2 s , MSWD = 0.53, n = 310), which was consistent with the reference value. Laser fluorination analyses yielded mean δ 18 O values of S513 were 11.71 ± 0.11‰ (2 s , MSWD = 0.25, n = 5). The results obtained with multiple analytical methods show that zircon S513 is homogeneous to 8% (1 s ) or better for contents of Y, Nb, Ce, Gd, heavy REE, Ta, U, Th, Pb and Hf. Additionally, the homogeneity is observed at 0.12‰ (2 s ) for U‐Pb ages, 1.8% (2 s ) for (U‐Th)/He ages, 0.0036% (2 s ) for Hf isotopes, and 0.11‰ (2 s ) for O isotope ratios. Zircon S513 is proposed as a new potential primary calibration or quality control reference material for microbeam U‐Th‐Pb geochronology and Hf‐O isotope measurement.