Appendix 1: Gem corundum age data from the literature, to accompany the article:
Liu, Y., Lu, R. & Pan, S. 2023. Characterisation and in situ age determination of zircon inclusions in sapphires from Muling, north-east China. Journal of Gemmology, 38(6), 564–581, https://doi.org/10.15506/JoG.2023.38.6.564.
Chemical data to accompany the article:
Hanser, C.S., Stephan, T., Gul, B., Häger, T. & Botcharnikov, R. 2023. Comparison of emeralds from the Chitral District, Pakistan, with other Pakistani and Afghan emeralds. Journal of Gemmology, 38(6), 582–599, https://doi.org/10.15506/JoG.2023.38.6.582.
Raman spectra of minerals in forsterite-serpentine to accompany the article:
Peng, B., He, M., Yang, M., Liu, X. & Sui, X. 2023. Mineralogical and gemmological characteristics of gem-quality forsterite-serpentine from north-eastern China. Journal of Gemmology, 38(6), 600–614, https://doi.org/10.15506/JoG.2023.38.6.600.