DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: RES-3
MINERAL_TYPE: Sulfate
MINERAL: Na-Alunite (Alunite Group)
FORMULA: NaAl3(SO4)2(OH)6
FORMULA_HTML: NaAl3(SO4)2(OH)6
COLLECTION_LOCALITY: Not available
ORIGINAL_DONOR: Roger Stroffregen
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
Synthetically prepared pure Na-endmember sample made at 450C. Sample composition is 100% mole fraction Na.
See: Stroffregen, R.E., and C.N. Alpers, Observations on the unit-cell dimensions, H2O contents, and delD values of natural and synthetic alunite, American Mineralogist, 77, 1092-1098, 1992.
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
see:Stroffregen, R.E., and C.N. Alpers, Observations on the unit-cell dimensions, H2O contents, and delD values of natural and synthetic alunite, American Mineralogist, 77, 1092-1098, 1992.
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: NONE #XRF, EPMA, ICP(Trace),WChem
COMPOSITION_TRACE: None
COMPOSITION_DISCUSSION:
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
Sample has relatively strong vibrational features between 1.4 - 1.5, 1.76, 2.17, 2.32, and 2.5 microns. Other pure Na-endmember alunites prepared at lower temperatures have much weaker vibrational features.
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1_2a3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns