Raman Spectroscopy Coupled with Reflectance Spectroscopy as a Tool for the Characterization of Key Hydrothermal Alteration Minerals in Epithermal Au–Ag Systems: Utility and Implications for Mineral Exploration
Raman spectroscopy of fine-grained hydrothermal alteration minerals, and phyllosilicates in particular, presents certain challenges. However, given the increasingly widespread recognition of field portable visible–near infrared–shortwave infrared (Vis-NIR-SWIR) spectroscopy as a valuable tool in the...
Published in: | Applied Spectroscopy |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
SAGE Publications
2021
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1177/00037028211047869 http://journals.sagepub.com/doi/pdf/10.1177/00037028211047869 http://journals.sagepub.com/doi/full-xml/10.1177/00037028211047869 |
id |
crsagepubl:10.1177/00037028211047869 |
---|---|
record_format |
openpolar |
spelling |
crsagepubl:10.1177/00037028211047869 2024-09-15T18:20:18+00:00 Raman Spectroscopy Coupled with Reflectance Spectroscopy as a Tool for the Characterization of Key Hydrothermal Alteration Minerals in Epithermal Au–Ag Systems: Utility and Implications for Mineral Exploration Arbiol, Carlos Layne, Graham D. 2021 http://dx.doi.org/10.1177/00037028211047869 http://journals.sagepub.com/doi/pdf/10.1177/00037028211047869 http://journals.sagepub.com/doi/full-xml/10.1177/00037028211047869 en eng SAGE Publications https://creativecommons.org/licenses/by-nc/4.0/ Applied Spectroscopy volume 75, issue 12, page 1475-1496 ISSN 0003-7028 1943-3530 journal-article 2021 crsagepubl https://doi.org/10.1177/00037028211047869 2024-08-27T04:23:38Z Raman spectroscopy of fine-grained hydrothermal alteration minerals, and phyllosilicates in particular, presents certain challenges. However, given the increasingly widespread recognition of field portable visible–near infrared–shortwave infrared (Vis-NIR-SWIR) spectroscopy as a valuable tool in the mineral exploration industry, Raman microspectroscopy has promise as an approach for developing detailed complementary information on hydrothermal alteration phases in ore-forming systems. Here we present exemplar high-quality Raman and Vis-NIR-SWIR spectra of four key hydrothermal alteration minerals (pyrophyllite, white mica, chlorite, and alunite) that are common in precious metal epithermal systems, from deposits on the island of Newfoundland, Canada. The results reported here demonstrate that Raman microspectroscopy can accurately characterize pyrophyllite, white mica, chlorite, and alunite and provide details on their compositional variation at the microscale. In particular, spectral differences in the 1000–1150 cm −1 white mica Raman band allows the distinction between low-Tschermak phases (muscovite, paragonite) and phases with higher degrees of Tschermak substitution (phengitic white mica composition). The peak position of the main chlorite Raman band shifts between 683 cm −1 for Mg-rich chlorite and 665 cm −1 for Fe-rich chlorite and can be therefore used for semiquantitative estimation of the Fe 2+ content in chlorite. Furthermore, while Vis-NIR-SWIR macrospectroscopy allows the rapid identification of the overall composition of the most abundant hydrothermal alteration mineral in a given sample, Raman microspectroscopy provides an in-depth spectral and chemical characterization of individual mineral grains, preserving the spatial and paragenetic context of each mineral and allowing for the distinction of chemical variation between (and within) different mineral grains. This is particularly useful in the case of alunite, white mica, and chlorite, minerals with extensive solid solution, where microscale ... Article in Journal/Newspaper Newfoundland SAGE Publications Applied Spectroscopy 000370282110478 |
institution |
Open Polar |
collection |
SAGE Publications |
op_collection_id |
crsagepubl |
language |
English |
description |
Raman spectroscopy of fine-grained hydrothermal alteration minerals, and phyllosilicates in particular, presents certain challenges. However, given the increasingly widespread recognition of field portable visible–near infrared–shortwave infrared (Vis-NIR-SWIR) spectroscopy as a valuable tool in the mineral exploration industry, Raman microspectroscopy has promise as an approach for developing detailed complementary information on hydrothermal alteration phases in ore-forming systems. Here we present exemplar high-quality Raman and Vis-NIR-SWIR spectra of four key hydrothermal alteration minerals (pyrophyllite, white mica, chlorite, and alunite) that are common in precious metal epithermal systems, from deposits on the island of Newfoundland, Canada. The results reported here demonstrate that Raman microspectroscopy can accurately characterize pyrophyllite, white mica, chlorite, and alunite and provide details on their compositional variation at the microscale. In particular, spectral differences in the 1000–1150 cm −1 white mica Raman band allows the distinction between low-Tschermak phases (muscovite, paragonite) and phases with higher degrees of Tschermak substitution (phengitic white mica composition). The peak position of the main chlorite Raman band shifts between 683 cm −1 for Mg-rich chlorite and 665 cm −1 for Fe-rich chlorite and can be therefore used for semiquantitative estimation of the Fe 2+ content in chlorite. Furthermore, while Vis-NIR-SWIR macrospectroscopy allows the rapid identification of the overall composition of the most abundant hydrothermal alteration mineral in a given sample, Raman microspectroscopy provides an in-depth spectral and chemical characterization of individual mineral grains, preserving the spatial and paragenetic context of each mineral and allowing for the distinction of chemical variation between (and within) different mineral grains. This is particularly useful in the case of alunite, white mica, and chlorite, minerals with extensive solid solution, where microscale ... |
format |
Article in Journal/Newspaper |
author |
Arbiol, Carlos Layne, Graham D. |
spellingShingle |
Arbiol, Carlos Layne, Graham D. Raman Spectroscopy Coupled with Reflectance Spectroscopy as a Tool for the Characterization of Key Hydrothermal Alteration Minerals in Epithermal Au–Ag Systems: Utility and Implications for Mineral Exploration |
author_facet |
Arbiol, Carlos Layne, Graham D. |
author_sort |
Arbiol, Carlos |
title |
Raman Spectroscopy Coupled with Reflectance Spectroscopy as a Tool for the Characterization of Key Hydrothermal Alteration Minerals in Epithermal Au–Ag Systems: Utility and Implications for Mineral Exploration |
title_short |
Raman Spectroscopy Coupled with Reflectance Spectroscopy as a Tool for the Characterization of Key Hydrothermal Alteration Minerals in Epithermal Au–Ag Systems: Utility and Implications for Mineral Exploration |
title_full |
Raman Spectroscopy Coupled with Reflectance Spectroscopy as a Tool for the Characterization of Key Hydrothermal Alteration Minerals in Epithermal Au–Ag Systems: Utility and Implications for Mineral Exploration |
title_fullStr |
Raman Spectroscopy Coupled with Reflectance Spectroscopy as a Tool for the Characterization of Key Hydrothermal Alteration Minerals in Epithermal Au–Ag Systems: Utility and Implications for Mineral Exploration |
title_full_unstemmed |
Raman Spectroscopy Coupled with Reflectance Spectroscopy as a Tool for the Characterization of Key Hydrothermal Alteration Minerals in Epithermal Au–Ag Systems: Utility and Implications for Mineral Exploration |
title_sort |
raman spectroscopy coupled with reflectance spectroscopy as a tool for the characterization of key hydrothermal alteration minerals in epithermal au–ag systems: utility and implications for mineral exploration |
publisher |
SAGE Publications |
publishDate |
2021 |
url |
http://dx.doi.org/10.1177/00037028211047869 http://journals.sagepub.com/doi/pdf/10.1177/00037028211047869 http://journals.sagepub.com/doi/full-xml/10.1177/00037028211047869 |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
Applied Spectroscopy volume 75, issue 12, page 1475-1496 ISSN 0003-7028 1943-3530 |
op_rights |
https://creativecommons.org/licenses/by-nc/4.0/ |
op_doi |
https://doi.org/10.1177/00037028211047869 |
container_title |
Applied Spectroscopy |
container_start_page |
000370282110478 |
_version_ |
1810458671084208128 |