COLLECTION_LOCALITY: Nipton, California, USA
ORIGINAL_DONOR: Wards Scientific
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION: Brown to pink veins in a highly fractured white matrix (barite).
X-ray diffraction analysis found quartz, barite and minor bastnesite (R. Driscoll).
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EPMA, ICP(Trace), WChem
SPECTROSCOPIC_DISCUSSION: The spectrum of this sample was measured on a brown and pink vein of bastnaesite. Bastnaesite Ward Sample WS320 XRD results show that the sample is contaminated with quartz and barite but both minerals do not have VNIR-SWIR absorption features and donít contribute to the REE absorptions between 0.35 and 2.1 microns. It should be representative of relatively pure bastnaesite. There are numerous intense sharp absorptions (f-f orbital electronic transitions) throughout the 0.35 to 2.5 micron region presumably due to variable proportions of lanthanide series rare earth elements (i.e., Nd, Sm, and others). Absorptions in the SWIR exhibit overlapping absorptions, broader bands and vibrational absorptions due to potential CO3 combination and overtone bands. This makes band assignment more difficult and multiple REEs could be present in a given wavelength region. (T. Hoefen and G. Swayze)
SPECTRAL_PURITY: 1b2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns