Identifying Galena with a Field Spectrometer

Galena is a lead sulfide with the chemical formula PbS. It is the primary ore for lead and also can contain minable quantities of silver. Galena with silver content is referred to as argentiferous galena. Galena is often associated with the minerals sphalerite, calcite and fluorite.

The NIR spectra for galena has wide absorption features around 560nm. SPECTRAL EVOLUTION offers a wide range of portable spectrometers for field measurements to identify galena in the field. Our mining spectrometers include the oreXpress, oreXplorer and oreXpert. These instruments are designed for field use—ruggedly built with no moving optical components to breakdown, running on lithium-ion batteries for a full day of scanning. The oreXpress is our standard unit with high resolution/high sensitivity, the oreXplorer has higher resolution and the oreXpert has the highest resolution available in a portable spectrometer to measure smaller features for more accurate identification especially in mineral mixtures.

These instruments area available with our EZ-ID mineral identification software. EZ-ID matches your target spectra against three libraries of over 1100 minerals: the USGS, SpecMIN and GeoSPEC libraries. EZ-ID allows you to select absorption features for closer examination using spectral match regions. Spectral match regions can be pre-set when looking for specific minerals during exploration. EZ-ID also provides scalars to enhance the geologist’s understanding of crystallinity changes, alteration pattern shifts and geochemical conditions. EZ-ID supports spectral scalars for Al-OH bonds, kaolinite crystallinity (Kx), illite spectral maturity (ISM), chlorite spectral maturity (CSM), Mg-OH bonds, Fe-OH bonds, Fe3t (mineral type), Fe3i (mineral intensity), and Al-Fe-Mg bonds. EZ-ID’s three libraries contain 10 spectra of known galena samples to match against.

Above is a close-up of a galena spectra matched to a known sample in the GeoSPEC high resolution library, one of three libraries available with EZ-ID.