The IAG supports an ongoing programme for the characterisation and distribution of high quality materials targeting the calibration of isotope ratio determinations based on in situ analytical methods. These include zircon 91500 for U-Th-Pb geochronology, apatites (δ37Cl and δ18O), sulphates (δ34S, δ18O) and tourmalines (Li, B and O isotope ratios). An osmium isotope reference solution (DROsS) is also available through the IAG.
Zircon 91500
This single crystal has been widely used for U-Th-Pb geochronology and δ18O studies; it has also been characterised for trace element and Hf-isotope contents. The relevant information is given in Wiedenbeck et al. (1995, 2004). A single aliquot of zircon 91500 consists of approximately 100 mg of sub-2 mm grains.
| Purchase Code | Name | Material | *Price |
| Zircon 91500 | Zircon 91500 | Zircon | 300 GBP |
| *discount available to IAG members | |||
Apatites
The apatite samples that we offer cover almost the full compositional space of the F-Cl-OH system as shown in the ternary plot below. The TUBAF series have been characterised for δ37Cl, apatites MZ-TH and ES-MM for δ18O, while both chlorine and oxygen isotopic data are available for apatites MGMH#133648 and MGMH#128441A. In all cases, a single aliquot consists of approximately 100 mg of sub-1.4 mm material.
| Purchase Code | Material(s) | Isotope systems | Citation | *Price |
| Apatite TUBAF#37 | TUBAF#37 |
δ37Cl |
Wudarska et al. (2021) | 150 GBP |
| Apatite TUBAF#38 | TUBAF#38 |
δ37Cl |
Wudarska et al. (2021) | 150 GBP |
| Apatite TUBAF#40 | TUBAF#40 |
δ37Cl |
Wudarska et al. (2021) | 150 GBP |
| Apatite TUBAF#50 | TUBAF#50 [a] |
δ37Cl |
Wudarska et al. (2021) | 300 GBP |
| Apatite MZ-TH | MZ-TH |
δ18O |
Wudarska et al. (2022) | 150 GBP |
| Apatite ES-MM | ES-MM |
δ18O |
Wudarska et al. (2022) | 300 GBP |
| MGMH Apatite set | MGMH#133648, MGMH#128441A |
δ37Cl, δ18O |
Wudarska et al. (2021, 2022) | 450 GBP |
| *discount available to IAG members | ||||
[a] There is very limited supply of this particular material and we therefore ask scientists interested in purchasing it to provide evidence of previous work on this isotope system.
Sulphates
Our list of sulphate reference materials includes anhydrite, gypsum and barite minerals characterised for δ18O and δ34S. These can be purchased individually or in sets consisting of either two anhydrites, two gypsums or three barites. Full details of their characterisation can be found in Li et al. (2023). In all cases, a single aliquot consists of approximately 100 mg of sub-1.4 mm material.
| Purchase Code | Material(s) | Isotope systems | Citation | *Price |
| Anhydrite 13491 | Anhydrite 13491 |
δ18O, δ34S |
Li et al. (2023) | 150 GBP |
| Anhydrite 40347 | Anhydrite 40347 |
δ18O, δ34S |
Li et al. (2023) | 150 GBP |
| Anhydrite set of 2 | Anhydrites 13491 and 40347 |
δ18O, δ34S |
Li et al. (2023) | 200 GBP |
| Barite 14898 | Barite 14898 |
δ18O, δ34S |
Li et al. (2023) | 150 GBP |
| Barite 16921 | Barite 16921 |
δ18O, δ34S |
Li et al. (2023) | 150 GBP |
| Barite 48628 | Barite 48628 |
δ18O, δ34S |
Li et al. (2023) | 150 GBP |
| Barite set of 3 | Barites 14898, 16921 and 48628 |
δ18O, δ34S |
Li et al. (2023) | 300 GBP |
| Gypsum 16655 | Gypsum 16655 |
δ18O, δ34S |
Li et al. (2023) | 150 GBP |
| Gypsum 37603 | Gypsum 37603 |
δ18O, δ34S |
Li et al. (2023) | 150 GBP |
| Gypsum set of 2 | Gypsums 16655 and 37603 |
δ18O, δ34S |
Li et al. (2023) | 200 GBP |
| *discount available to IAG members | ||||
Other Isotope RMs
These include tourmalines characterised for Li, B and O isotope ratios. These are the same materials as described under in the section headed “Reference Materials for Light Elements” under Elemental Microanalytical RMs
The Durham Romil Osmium Solution prepared at the University of Durham, UK, as an osmium isotope reference solution is also available through the IAG.
| Purchase Code | Material(s) | Isotope systems | Citation | *Price |
| Tourmaline set | Dravite, Schorl, Elbaite [b] |
δ7Li, δ11B, δ18O |
Leeman and Tonarini (2001), Wiedenbeck et al. (2021) | 450 GBP |
| Osmium solution | DROsS |
Os |
Luguet et al. (2008) | 150 GBP |
| *discount available to IAG members | ||||
References for Isotope Ratio materials:
Leeman W.P. and Tonarini S. (2001). Boron isotopic analysis of proposed borosilicate mineral reference samples. Geostandards Newsletter, 25(2-3), 399-403
Li, B et al. (2023). Barite, anhydrite and gypsum reference materials for in situ oxygen and sulfur isotope ratio measurements. Geostandards and Geoanalytical Research doi.org/10.1111/ggr.12533
Luguet A., Nowell G.M. and Pearson D.G. (2008). 184Os / 188Os and 186Os / 188Os measurements by Negative Thermal Ionisation Mass Spectrometry (N-TIMS): Effects of interfering element and mass fractionation corrections on data accuracy and precision. Chemical Geology, 248(3-4), 342-62
Wiedenbeck, M et al. (1995). Three Natural Zircon Standards For U-Th-Pb, Lu-Hf, Trace Element and REE Analyses. Geostandards Newsletter, 19(1), 1-23. https://doi.org/10.1111/j.1751-908X.1995.tb00147.x
Wiedenbeck, M et al. (2004). Further Characterisation of the 91500 Zircon Crystal. Geostandards and Geoanalytical Research, 28(1), 9-39. https://doi.org/10.1111/j.1751-908X.2004.tb01041.x
Wiedenbeck M., et al. (2021). Tourmaline reference materials for the in situ analysis of oxygen and lithium isotope ratio compositions. Geostandards and Geoanalytical Research, 45/1, doi.org/10.1111/ggr.12362.
Wudarska, A. et al. (2021). Inter‐laboratory characterisation of apatite reference materials for chlorine isotope analysis. Geostandards and Geoanalytical Research, doi.org/10.1111/ggr.12366.
Wudarska, A. et al. (2022). Characterisation of apatite reference materials for oxygen isotope analysis and associated methodological considerations. Geostandards and Geoanalytical Research doi.org/10.1111/ggr.12416