Ultraviolet-photoluminescence and trace element analyses in Ga-rich sphalerite from the Djebel Gustar Zn-Pb deposit, Algeria

Aleš Šoster (Author), Viktor Bertrandsson Erlandsson (Author), Miloš Velojić (Author), Phillip Gopon (Author)

Abstract

The Djebel Gustar Zn-Pb deposit in northeastern Algeria is one of many carbonate-hosted base metal deposits in the Atlas metallogenic province of North Africa. The sphalerite in this deposit occurs in five distinct types that differ in texture, mineral assemblage, chemical composition, and UV photoluminescence signature. Detailed investigation of trace elements by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) showed that the sphalerite is significantly enriched in the critical metal Ga. The trace element concentrations of the different sphalerite types correlated well with their photoluminescence color; with Mn$^{2+}$ (orange-yellow), Cu$^+$ (green), and Ga$^{3+}$ (red) being the dominant activators. We suggest that the Ga enrichment in the Djebel Gustar deposit is the result of formation conditions that include the mixing of a Cl-rich fluid carrying mainly Zn and Pb with a more reduced and Cl-poor fluid containing considerable organic matter and/or calcite with adsorbed Ga(OH)$_3$. This Ga was subsequently incorporated into sphalerite, rather than forming a stoichiometric Ga phase. Furthermore, our study demonstrates that UV photoluminescence of low Fe sphalerite has the potential to become a simple and affordable tool for preliminary characterization of sphalerite ores in mining and exploration with respect to critical elements such as Ga.

Keywords

sphalerite;gallium;mineral chemistry;critical metal;LA-ICP-MS;

Data

Language:	English
Year of publishing:	2023
Typology:	1.01 - Original Scientific Article
Organization:	UL NTF - Faculty of Natural Sciences and Engineering
UDC:	55
COBISS:	151214595
ISSN:	0169-1368
Views:	14
Downloads:	3
Average score:	0 (0 votes)
Metadata:

Other data

Type (COBISS):	Article
Pages:	str. 1-14
Issue:	ǂVol. ǂ157
Chronology:	2023
DOI:	10.1016/j.oregeorev.2023.105474
ID:	19857803