DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: AL706
MINERAL_TYPE: Sulfate
MINERAL: Alunite (Alunite group)
FORMULA: NaAl3(SO4)2(OH)6
FORMULA_HTML: NaAl3(SO4)2(OH)6
COLLECTION_LOCALITY: Sulfur, Nevada
ORIGINAL_DONOR: Ron Lyon, Stanford University
CURRENT_SAMPLE_LOCATION: CSES/CIRES, Univ. of CO, Boulder
ULTIMATE_SAMPLE_LOCATION: CSES/CIRES, Univ. of CO, Boulder
SAMPLE_DESCRIPTION: Composition determined to be natroalunite (Na=100) endmember based on position of the 1.496 micron OH overtone absorption using Swayze and other (2014) wavelength correlation method. See: Swayze, G.A., Clark, R.N., Goetz, A.F.H., Livo, K.E., Breit, G.N., Kruse, F.A., Sutly, S.J., Snee, L.W., Lowers, H.A., Post, J.L., Stoffregen, R.E., and Ashley, R.P., 2014, Mapping advanced argillic alteration at Cuprite, Nevada, using imaging spectroscopy: Economic Geology, v. 109, p. 1179-1221.
IMAGE_OF_SAMPLE:
NO PHOTO
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
Alunite
Contaminant phases: smectite, quartz, minor amounts.
Kruse, F.A., and P.L. Hauff, eds., 1992, The IGCP-264 Spectral Properties Database. IUSG/UNESCO, Special Publication, 211p., (in press).
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EPMA, ICP(Trace), WChem
COMPOSITION_TRACE: None
COMPOSITION_DISCUSSION:
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
avg. grain size = 15 µm
Length fast, 1st order gray, sample looks pure but small grain size prevents
determination of optical sign. G. Swayze.
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1b2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns