oa Rapid field identification of LCT pegmatite mineralogy: Application of portable Raman spectroscopy

Rapid field identification of mineralogy is critical for exploration and ore extraction. For LCT pegmatites, a significant challenge is presented as many dominant minerals are visually similar and many of these minerals cannot be identified by commonly used methods such as SWIR or pXRF analysis. Therefore, being able to readily identify full mineralogy, especially of key lithium bearing minerals such as eucryptite, petalite and spodumene, is invaluable.

Field portable Raman spectroscopy was evaluated, and an application developed to identify and delineate the dominant mineralogy of the Pioneer Sinclair deposit. Raman is a form of vibrational spectroscopy and can readily identify key pegmatite minerals such as quartz, feldspars, micas, Li-silicates, beryls, tourmalines etc.

Over 8,000 Raman spectra were collected from RC, diamond drill holes and grade control samples. The main mineral components were identified by spectral matching to a custom LCT pegmatite reference library and were further delineated by the extraction of key spectral features.

The mineralogical results from these samples were then applied for the identification of pegmatite zones and the development of mineralogical maps of the deposit. Raman analysis of grade control samples identified the core pollucite zone in agreement with pXRF analysis and is being used to augment geological mapping and mineral zonation definition ahead of further exploration. Field portable Raman spectroscopy was found to be a powerful tool for rapid mineral identification and will have useful applications for the exploration and mining of LCT pegmatites and other commodities.