Title
Mineral Interpretation Discrepancies Identified between Infrared Reflectance Spectra and X-ray Diffractograms
Abstract
Mineral composition can be determined using different methods such as reflectance spectroscopy and X-ray diffraction (XRD). However, in some cases, the composition of mineral maps obtained from reflectance spectroscopy with XRD shows inconsistencies in the mineral composition interpretation and the estimation of (semi-)quantitative mineral abundances. We show why these discrepancies exist and how should they be interpreted. Part of the explanation is related to the sample choice and preparation; another part is related to the fact that clay minerals are active in the short-wave infrared, whereas other elements in the composition are not. Together, this might lead to distinctly different interpretations for the same material, depending on the methods used. The main conclusion is that both methods can be useful, but care should be given to the limitations of the interpretation process. For infrared reflectance spectroscopy, the lack of an actual threshold value for the H-OH absorption feature at 1900 nm and the poorly defined Al-OH absorption feature at 2443 nm, as well as for XRD, detection limit, powder homogenizing, and the small amount of montmorillonite below 1 wt.%, was the source of discrepancies.
Year
DOI
Venue
2021
10.3390/s21206924
SENSORS
Keywords
DocType
Volume
shortwave infrared, X-ray powder diffraction, discrepancy, clay mineral interpretation, hydrothermal alteration minerals
Journal
21
Issue
ISSN
Citations 
20
1424-8220
1
PageRank 
References 
Authors
0.63
0
5
Name
Order
Citations
PageRank
Fardad Maghsoudi Moud110.96
Fiorenza Deon210.63
Mark van der Meijde311.30
Frank van Ruitenbeek410.96
Rob Hewson510.96