HANUS, Radek,
Kamil SOBEK, Kamila JOHNOVÁ, Tomáš TROJEK, Ján ŠTUBŇA, Tomáš HANUS and Kamila JUNGMANNOVÁ. Hyalite Opal from Erongo, Namibia, Showing Green Daylight Fluorescence.
Journal of Gemmology. Gemmological Association of Great Britain, 2022, vol. 38, No 2, p. 172-182. ISSN 1355-4565. Available from: https://dx.doi.org/10.15506/JoG.2022.38.2.172.