DETERMINATION OF K/RB-LI SYSTEMATICS OF MICROCLINE FROM HANDHELD LIBS ANALYSIS

As the volume of electronic vehicle production increases yearly, the need for lithium and the exploration for Li-Cs-Ta (LCT) granitic pegmatites increases. There is also the need for the elemental detection and identification of certain key elements that are a part of these LCT pegmatites. Handheld laser-induced breakdown spectroscopy (LIBS) provides a means for rapid, in-field detection and quantification of certain key elements e.g. (Li, K, Rb, & Cs) useful in Li-pegmatite exploration and prospect evaluation. Based on the successful demonstration that Li-K/Rb systematics in mica can provide insight into extent of pegmatite fractionation and therefore spodumene mineralization potential (Wise et al., 2022, Minerals 12:77), this project investigated if the same approach can be applied to handheld LIBS analysis of feldspar. A Z-903 handheld LIBS analyzer (SciAps Inc., Andover, MA, USA) was calibrated using the Profile Builder software for the quantitative analysis of Li, K, and Rb and selected other elements (Mg, Ca, Ga, Sr, Cs, Ba) using a suite of microcline samples whose compositions were known from LA-ICP-MS analysis. Each calibration was optimized by normalization of the emission intensities for the element of interest to selected emission peaks of elements on the same spectrometer of the LIBS analyzer. These calibrations were then tested on feldspar sample suites from pegmatites in North Carolina and Virginia.