Sample Description USGS Spectral Library Version 7

USGS Spectral Library Version 7 Sample Description

Kokaly, R.F., Clark, R.N., Swayze, G.A., Livo, K.E., Hoefen, T.M., Pearson, N.C., Wise, R.A., Benzel, W.M., Lowers, H.A., Driscoll, R.L., and Klein, A.J., 2017, USGS Spectral Library Version 7: U.S. Geological Survey Data Series 1035, 61 p., https://doi.org/10.3133/ds1035
_{For more information on the library, see:
local link
web link}

TITLE: Riebeckite NMNH122689 Amphibole DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: NMNH122689

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.

IMAGE_OF_SAMPLE:
NO PHOTO

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, EPMA, 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 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:

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

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1a2_3_4_ # NMNH122689 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns