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Clark et. al. 2003 USGS Open File Report 03-395
Spectral Library splib05a Sample Description

(For further information on spectrsocopy, see: http://speclab.cr.usgs.gov)

TITLE: Olivine HS285 Fo80 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS285

MINERAL_TYPE: Nesosilicate

MINERAL: Olivine (Olivine group)

FORMULA: Mg2SiO4-Fe2SiO4 Fo80

FORMULA_HTML: Mg2SiO4-Fe2SiO4 Fo80

COLLECTION_LOCALITY: Arizona

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

A spectrum for this sample was published in: Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1973, Visible and near-infrared spectra of minerals and rocks: VI. Additional silicates. Modern Geology, v. 4, p. 85-106.

With the note that the sample is Peridot, and the following comment: "This is a gem quality olivine which is 80Fo-20Fa. It contains a small amount of spinel as well as displaying a trace of iron oxide stain. The ferric iron band at 0.64µm is prominent in the larger particle size sample."

The sample measured for the library was the largest sieve interval, 4B, 250-1200µm.

For additional information on the spectra of olivine's see: King, T.V.V. and W.I. Ridley, 1987, Relation of the Spectroscopic Reflectance of Olivine to Mineral Chemistry and Some Remote Sensing Implications. J. Geophys. Res., 11,457-11,469.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 7.0-9.5 keV
File: oliv285.mdi (smear on quartz plate)
References: PDF2 #34-0189
Found: Forsterite

Comments: Sharp peaks show good resolution of the alpha1-alpha2 components. Some peaks have slight shoulders toward larger d-spacings. PDF2 34-0189 (synthetic forsterite) is an excellent match for HS-285, much better than 31-0795 (ferroan forsterite). One very weak peak at 2.85 angstroms has not been identified. The shoulders could be caused by slight Fe-Mg zoning.

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

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

LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment
LIB_SPECTRA: splib04a r 3625 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 5115 0.2-3.0µm 200 g.s.=


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