Hyalite Opal from Erongo, Namibia, Showing Green Daylight Fluorescence

Investor logo

Warning

This publication doesn't include Faculty of Arts. It includes Faculty of Science. Official publication website can be found on muni.cz.
Authors

HANUS Radek SOBEK Kamil JOHNOVÁ Kamila TROJEK Tomáš ŠTUBŇA Ján HANUS Tomáš JUNGMANNOVÁ Kamila

Year of publication 2022
Type Article in Periodical
Magazine / Source Journal of Gemmology
MU Faculty or unit

Faculty of Science

Citation
Web https://gem-a.com/jog-volume-38-issue-2-2022
Doi http://dx.doi.org/10.15506/JoG.2022.38.2.172
Keywords Hyalite; Uranyl ion; Raman spectroscopy; Gamma spectroscopy; Photoluminescence
Description Rare hyalite opal showing green daylight fluorescence was discovered in the Erongo region, Namibia, sometime prior to 2000. Raman spectroscopy confirms this hyalite to be opal-A, and the most interesting feature of the Raman spectra are bands associated with the hydroxyl-stretching regions in the mineral’s structure. A doublet at 3602/3665 cm–1 appears to be unique to opal from this locality and may be due to the vibration of water in an unusual structural-binding arrangement. Trace amounts of the uranyl molecule (UO2)2+ are responsible for the luminescence, which is unevenly distributed according to the opal’s botryoidal structure. Measured radioactivity values are similar to those reported for other daylight-fluorescing opals (e.g. from Mexico), and are well below the global average terrestrial gamma dose rate.
Related projects:

You are running an old browser version. We recommend updating your browser to its latest version.