Calibrating a Handheld LIBS for Li Exploration in the Barroso-Alvao Aplite-Pegmatite Field, Northern Portugal: Textural Precautions and Procedures When Analyzing Spodumene and Petalite

• Type: Article in International Scientific Journal
• Date: 2023

Authors

Dias, F (Author) Other; Ribeiro, R (Author) FCUP; Goncalves, F (Author) Other; Alexandre Lima (Author) FCUP; Roda-Robles, E (Author) Other; Martins, T (Author) Other

Journal

Title: Minerals

Vol. 13

Final page: 470

Publisher: MDPI

Indexing

ISI Web of Knowledge - 0 Citations

Scopus

Other information

Authenticus ID: P-00Y-5K5

DOI: 10.3390/min13040470

Abstract (EN): In pegmatites containing abundant petalite and spodumene, such as those from the Barroso-Alvao (BA) aplite-pegmatite field, calibrating a portable laser-induced breakdown spectroscopy (pLIBS) equipment to identify and analyze these minerals may be challenging. Forty-nine samples of spodumene, petalite and spodumene + quartz were collected from 22 aplite-pegmatites from the BA field and sent for inductively coupled plasma-mass spectroscopy analysis. One calibration for both spodumene and petalite has been proven to be impossible since almost all the LIBS intensity ratios, including for Li, overlapped on both minerals. Thus, three calibrations were developed: one qualitative to distinguish both minerals and two more quantitative, specifically made for each mineral. The first LIBS calibration only has Fe since it is the sole element with intensity ratios different enough to distinguish both minerals. Eleven calibration lines were created: Li, Al, Si, Be, Na, P, K, Mn, Fe, Rb and Cs; however, only the Li, Al, and Si have consistent errors below 20%. Thin sections were produced and observed with optical microscopy and cathodoluminescence (CL) to control the purity and mineral paragenesis of the samples. The petalite pellets were also controlled with cold CL since petalite crystals often present fine spodumene and quartz inclusions.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 31