DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: GDS140
MINERAL_TYPE: Sulfate
MINERAL: Eugsterite
FORMULA: Na4Ca(SO4)3*2H2O
FORMULA_HTML: Na4Ca(SO4)3•2H2O
COLLECTION_LOCALITY: X-rayed (Synthetic)
ORIGINAL_DONOR: Jim Crowley
CURRENT_SAMPLE_LOCATION: USGS Reston, Virginia
ULTIMATE_SAMPLE_LOCATION: USGS Reston, Virginia
SAMPLE_DESCRIPTION:
Hydrous
evaporation of Na2SO4 + CaSO4 solution at 70°C
Spectrum originally published in:
Crowley, J.K., 1991, Visible and Near-Infrared (0.4 - 2.5µm)
Reflectance Spectra of Playa Evaporite Minerals: Journal of
Geophysical Research, vol 96, no.B10, p. 16,231-16,240.
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
Sample is eugsterite but contains a small amount of gypsum (Crowley, 1991)
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EPMA, ICP(Trace), WChem
COMPOSITION_TRACE: None
COMPOSITION_DISCUSSION:
evaporation of Na2SO4 + CaSO4 solution at 70°C
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1b2b3b4u # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns