Obscuration of Crystalline Ca-Sulfate in XRD And Raman Data when Coated by Amorphous Ferric Sulfate: Implications for the Amorphous Components at Gale Crater

Raman Data: There are 5 data files in txt format that contain several Raman spectra of the samples studied in the associated journal article. These five file names are listed below. · AFS Raman.txt: Raman spectra of the pure amorphous ferric sulfate (AFS). · Gypsum Raman.txt: Raman spectra of 25-63 µm gypsum. · Mikasaite Raman.txt: Raman spectra of Mikasaite · Coated Gyp-AFS Raman.txt: 50-50 wt% mixture of AFS and gypsum, with the AFS coating the gypsum. · Uncoated Gyp-Raman.txt: 50-50 wt% mixture of AFS and gypsum, with the AFS and gypsum in separate discrete grains. File Structure: Each txt file for each sample contains 5 spectra. Below is a guide to each column in the files · Column 1: Raman Shift (1/cm) · Column 2: Raw uncorrected spectra · Column 3: Baseline · Column 4: Baseline-Corrected spectra · Column 5: Normalized Baseline-Corrected spectra, with offset shown in Figure 1. XRD Data: The raw diffraction data of both the coated and uncoated Gyp-AFS mixtures from both XRD instruments are available. The file names are listed below, with descriptions · 50-50_gyp-AFS_Coated_DS_XRD.txt · 50-50_gyp-AFS_Uncoated_DS_XRD.txt · Gyp-AFS-Coated_BB_XRD.ras · Gyp-AFS-Uncoated_BB_XRD.ras The two files ending with ‘.txt’ with ‘DS’ in the file name contain diffraction data taken with the Olympus BTX XRD instrument. The two files ending with ‘.ras’ with ‘BB’ in the file name contain diffraction data taken with the Rigaku Miniflex XRD. SEM/EDS Data: There are 13 SEM images available in high-resolution of both the uncoated and coated Gyp-AFS samples. The file name states that whether the sample is coated or uncoated. The scale bar and scan information is at the bottom of each SEM images. Additionally, a word document 'Gyp-AFS SEM-EDS Full.docx' holds all of the full EDS analyses of each image, with spot spectra and line scans.