Insights on Structure and Threshold Detection Limits of Stichtite (Magnesium-Chromium Carbonate-Hydroxide) by Fourier Transform Infrared Analysis
Spectral features for natural stichtite at 1042, 1096, 1360, 1638, and 3482 cm<sup>−1</sup> provide insights on mineral structure, with peaks consistent with OH<sup>−</sup> stretching modes bound to Mg or Cr, CO<sub>3</sub><sup>2ͨ...
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doaj-b08e12f5ba3945678f862f5266a5471f2020-11-25T01:55:07ZengMDPI AGMinerals2075-163X2020-02-0110321510.3390/min10030215min10030215Insights on Structure and Threshold Detection Limits of Stichtite (Magnesium-Chromium Carbonate-Hydroxide) by Fourier Transform Infrared AnalysisErik Melchiorre0Andy Garcia1Maryjo Brounce2Department of Geological Sciences, California State University of San Bernardino, 5500 University Parkway, San Bernardino, CA 92407, USADepartment of Geological Sciences, California State University of San Bernardino, 5500 University Parkway, San Bernardino, CA 92407, USADepartment of Earth and Planetary Sciences, University of California Riverside, 900 University Avenue, Riverside, CA 92521, USASpectral features for natural stichtite at 1042, 1096, 1360, 1638, and 3482 cm<sup>−1</sup> provide insights on mineral structure, with peaks consistent with OH<sup>−</sup> stretching modes bound to Mg or Cr, CO<sub>3</sub><sup>2−</sup> antisymmetric stretches and CO<sub>3</sub><sup>2−</sup> bound within the sample and molecular water. These Infrared (IR) data suggest natural stichtite forms at a pH of >12 with increased water and decreased carbonate in the interlayer due to a smaller interlayer distance and unit cell. Higher pH favors lower divalent cation purity and may explain observed ranges of non-end member compositions in stichtite from localities around the world, and across geologic time. This constrains stichtite formation to a range of very high pH conditions and is consistent with active serpentinizing fluid vents and some mine wastes. IR has clear application for the detection and quantification of stichtite under field and laboratory conditions within the detection limits of 5% stichtite within a serpentine host. The size and grade of terrestrial stichtite deposits, and resolution of remote sensing instruments, suggest remote IR detection of stichtite is possible, and remote IR detection for Earth and Mars is discussed.https://www.mdpi.com/2075-163X/10/3/215fourier transform infrared (ftir)stichtiteserpentinethreshold detectioninterlayer |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Erik Melchiorre Andy Garcia Maryjo Brounce |
spellingShingle |
Erik Melchiorre Andy Garcia Maryjo Brounce Insights on Structure and Threshold Detection Limits of Stichtite (Magnesium-Chromium Carbonate-Hydroxide) by Fourier Transform Infrared Analysis Minerals fourier transform infrared (ftir) stichtite serpentine threshold detection interlayer |
author_facet |
Erik Melchiorre Andy Garcia Maryjo Brounce |
author_sort |
Erik Melchiorre |
title |
Insights on Structure and Threshold Detection Limits of Stichtite (Magnesium-Chromium Carbonate-Hydroxide) by Fourier Transform Infrared Analysis |
title_short |
Insights on Structure and Threshold Detection Limits of Stichtite (Magnesium-Chromium Carbonate-Hydroxide) by Fourier Transform Infrared Analysis |
title_full |
Insights on Structure and Threshold Detection Limits of Stichtite (Magnesium-Chromium Carbonate-Hydroxide) by Fourier Transform Infrared Analysis |
title_fullStr |
Insights on Structure and Threshold Detection Limits of Stichtite (Magnesium-Chromium Carbonate-Hydroxide) by Fourier Transform Infrared Analysis |
title_full_unstemmed |
Insights on Structure and Threshold Detection Limits of Stichtite (Magnesium-Chromium Carbonate-Hydroxide) by Fourier Transform Infrared Analysis |
title_sort |
insights on structure and threshold detection limits of stichtite (magnesium-chromium carbonate-hydroxide) by fourier transform infrared analysis |
publisher |
MDPI AG |
series |
Minerals |
issn |
2075-163X |
publishDate |
2020-02-01 |
description |
Spectral features for natural stichtite at 1042, 1096, 1360, 1638, and 3482 cm<sup>−1</sup> provide insights on mineral structure, with peaks consistent with OH<sup>−</sup> stretching modes bound to Mg or Cr, CO<sub>3</sub><sup>2−</sup> antisymmetric stretches and CO<sub>3</sub><sup>2−</sup> bound within the sample and molecular water. These Infrared (IR) data suggest natural stichtite forms at a pH of >12 with increased water and decreased carbonate in the interlayer due to a smaller interlayer distance and unit cell. Higher pH favors lower divalent cation purity and may explain observed ranges of non-end member compositions in stichtite from localities around the world, and across geologic time. This constrains stichtite formation to a range of very high pH conditions and is consistent with active serpentinizing fluid vents and some mine wastes. IR has clear application for the detection and quantification of stichtite under field and laboratory conditions within the detection limits of 5% stichtite within a serpentine host. The size and grade of terrestrial stichtite deposits, and resolution of remote sensing instruments, suggest remote IR detection of stichtite is possible, and remote IR detection for Earth and Mars is discussed. |
topic |
fourier transform infrared (ftir) stichtite serpentine threshold detection interlayer |
url |
https://www.mdpi.com/2075-163X/10/3/215 |
work_keys_str_mv |
AT erikmelchiorre insightsonstructureandthresholddetectionlimitsofstichtitemagnesiumchromiumcarbonatehydroxidebyfouriertransforminfraredanalysis AT andygarcia insightsonstructureandthresholddetectionlimitsofstichtitemagnesiumchromiumcarbonatehydroxidebyfouriertransforminfraredanalysis AT maryjobrounce insightsonstructureandthresholddetectionlimitsofstichtitemagnesiumchromiumcarbonatehydroxidebyfouriertransforminfraredanalysis |
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