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: Riebeckite NMHN122689 Amphibole DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: NMHN122689

MINERAL_TYPE: Inosilicate

MINERAL: Riebeckite (Amphibole group)

FORMULA: Na2Fe(+2)3Fe(+3)2Si8O22(OH)2

FORMULA_HTML: Na₂Fe₃⁺²Fe₂⁺³Si₈O₂₂(OH)₂

COLLECTION_LOCALITY: Hurricane Mountain, Conway, New Hampshire

ORIGINAL_DONOR: National Museum of Natural History

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Individual grains of riebeckite appear very pure under the microscope (less than 1% impurities).

Salisbury, J. W., Walter, L. W., and Vergo, N., 1987, Mid-Infrared (2.1-25µm) Spectra of Minerals: First Edition, U.S. Geological Survey Open File Report 87-263.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Pure reibeckite.

Salisbury, J. W., Walter, L. W., and Vergo, N., 1987, Mid-Infrared (2.1-25µm) Spectra of Minerals: First Edition, U.S. Geological Survey Open File Report 87-263.

END_XRD_ANALYSIS.

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

COMPOSITION KEYWORD	Oxide ASCII	Amount	Weight Percent, %	Oxide html
COMPOSITION:	SiO2	50.32	wt%	SiO2
COMPOSITION:	TiO2	0.53	wt%	TiO2
COMPOSITION:	Al2O3	0.86	wt%	Al2O3
COMPOSITION:	FeO	35.27	wt%	FeO
COMPOSITION:	MnO	1.12	wt%	MnO
COMPOSITION:	MgO	0.07	wt%	MgO
COMPOSITION:	CaO	0.08	wt%	CaO
COMPOSITION:	Na2O	7.95	wt%	Na2O
COMPOSITION:	K2O	1.41	wt%	K2O
COMPOSITION:	Total	97.61	wt%

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

Microprobe analysis of hand-picked sample shows it to be homogeneous within and between grains, with typical riebeckite composition. Average of 10 samples.

Salisbury, J. W., Walter, L. W., and Vergo, N., 1987, Mid-Infrared (2.1-25µm) Spectra of Minerals: First Edition, U.S. Geological Survey Open File Report 87-263.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1a2_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 4241	0.2-3.0µm	200	g.s.=
LIB_SPECTRA:	splib05a r 5978	0.2-3.0µm	200	g.s.=

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U.S. Department of the Interior | U.S. Geological Survey URL: https://pubsdata.usgs.gov/pubs/of/2003/ofr-03-395/DESCRIPT/M/riebeckite_nmnh122689.html Questions or Assistance: USGS Web Contact Page Last Modified: Sat Jan 12 23:34 EST 2013