Distinguishing Between Lepidolite and Muscovite

with a Field Spectrometer

Lepidolite and muscovite are two micas that  often occur together in pegmatites. Both are phyllosilicate minerals and members of the polylithionite-trilithionite series.

Lepidolite is a source of lithium in minable quantities. Lithium is in demand for batteries from small batteries in phones to large batteries in electronic and hybrid vehicles.

An NIR full range (350-2500nm)  spectrometer from SPECTRAL EVOLUTION can be used with EZ-ID mineral identification software to distinguish between  lepidolite and muscovite.

Lepidolite has absorption features at 580, 2190 and 2340nm. Muscovite has features at 1400, 1900, 2190 ands 2210nm.

SPECTRAL EVOLUTION provides the oreXpert, oreXplorer and oreXpress field spectrometers with EZ-ID mineral identification software that matches your target sample against three libraries of known samples—the USGS, SpecMIN and GeoSPEC high resolution library. EZ-ID’s three libraries contain 2600 spectra for almost 1100 minerals. EZ-ID allows a geologist to unmix minerals from samples by using match regions to focus on certain absorption features. These match regions can be saved as pre-sets for easier discovery of similar minerals in the field. Scalars are also displayed to enhance the geologist’s understanding of crystallinity changes, alteration pattern shifts and geochemical conditions.

Scan of muscovite (green) plotted against a scan of lepidolite (blue) in DARWin SP Data Acquisition
software.

A scan of lepidolite matched to the GeoSPEC high resolution library.

A scan of muscovite matched to the GeoSPEC high resolution library.