TITLE: Desert_Varnish ANP90-14 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: ANO90-14

MINERAL_TYPE: Mineral mixture (Birnessite + hematite and clays)

MINERAL: Desert_Varnish

FORMULA: Na4Mn14O27*9H20 + alpha-Fe2O3 + clays

FORMULA_HTML: Na4Mn14O27•9H2O + alpha-Fe2O3

COLLECTION_LOCALITY: Arches National Park

ORIGINAL_DONOR: Greg Swayze

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

"Desert varnish invariably consists of birnessite in intimate mixture with hematite and large amounts of clay minerals. The clays are generally of the illite-montmorillonite type with minor kaolinite, but in several reversed."

Potter, R.M. and G.R. Rossman, 1979, Mineralogy of manganese dendrites and coatings. American Mineralogist, v.64, pp 1219-1226.

This sample is a coating on sandstone.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1_2_3_4_

LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment

LIB_SPECTRA: splib04a r 1374 0.2-3.0µm 200 g.s.=

LIB_SPECTRA: splib05a r ____ 0.2-3.0µm 200 g.s.=

LIB_SPECTRA: splib06a r ____ 1.5-25µm 250 g.s.=