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:
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web link}

TITLE: Sepiolite SepSp-1.AcB DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: SepSp-1.AcB (1-26-87)

MINERAL_TYPE: Phyllosilicate

MINERAL: Sepiolite (meerschaum)

FORMULA: Mg4Si6O15(OH)2*H2O

FORMULA_HTML: Mg₄Si₆O₁₅(OH)₂•H₂O

COLLECTION_LOCALITY: Valdemoro, Spain

ORIGINAL_DONOR: Source Clay Mineral Repository

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Sepiolite is a hydrous magnesium silicate, claylike and a secondary mineral associated with serpentine.

IMAGE_OF_SAMPLE:
NO PHOTO

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Calcite removed from this split during treatment with Na-acetate buffer. (Norma Vergo).

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: XRF # XRF, EPMA, ICP(Trace), WChem

COMPOSITION
KEYWORD Oxide
ASCII Amount Weight
Percent, % Oxide
html

COMPOSITION: SiO2 54.8 wt% SiO₂

COMPOSITION: TiO2 0.04 wt% TiO₂

COMPOSITION: Al2O3 1.39 wt% Al₂O₃

COMPOSITION: Fe2O3 0.40 wt% Fe₂O₃

COMPOSITION: FeO 0.02 wt% FeO

COMPOSITION: MnO less than 0.02 wt% MnO

COMPOSITION: MgO 22.3 wt% MgO

COMPOSITION: CaO 1.07 wt% CaO

COMPOSITION: Na2O less than 0.15 wt% Na₂O

COMPOSITION: K2O 0.20 wt% K₂O

COMPOSITION: P2O5 less than 0.05 wt% P₂O₅

COMPOSITION: H2O+ 11.4 wt% H₂O⁺

COMPOSITION: H2O- 7.36 wt% H₂O^-

COMPOSITION: H2O 18.8 wt% H₂O

COMPOSITION: LOI 18.1 wt% LOI

COMPOSITION: Total 98.72 wt%

COMPOSITION: O=Cl,F,S wt% #correction for Cl, F, S

COMPOSITION: New Total 98.72 wt%

COMPOSITION KEYWORD	Oxide ASCII	Amount	Weight Percent, %	Oxide html
COMPOSITION:	SiO2	54.8	wt%	SiO₂
COMPOSITION:	TiO2	0.04	wt%	TiO₂
COMPOSITION:	Al2O3	1.39	wt%	Al₂O₃
COMPOSITION:	Fe2O3	0.40	wt%	Fe₂O₃
COMPOSITION:	FeO	0.02	wt%	FeO
COMPOSITION:	MnO	less than 0.02	wt%	MnO
COMPOSITION:	MgO	22.3	wt%	MgO
COMPOSITION:	CaO	1.07	wt%	CaO
COMPOSITION:	Na2O	less than 0.15	wt%	Na₂O
COMPOSITION:	K2O	0.20	wt%	K₂O
COMPOSITION:	P2O5	less than 0.05	wt%	P₂O₅
COMPOSITION:	H2O+	11.4	wt%	H₂O⁺
COMPOSITION:	H2O-	7.36	wt%	H₂O^-
COMPOSITION:	H2O	18.8	wt%	H₂O
COMPOSITION:	LOI	18.1	wt%	LOI
COMPOSITION:	Total	98.72	wt%
COMPOSITION:	O=Cl,F,S		wt%	#correction for Cl, F, S
COMPOSITION:	New Total	98.72	wt%

COMPOSITION_TRACE: Exists but needs to be included.

COMPOSITION_DISCUSSION:

Analysis by E. Brandt, J.H. Christie, J. Taggart, Ardith J. Bartel, K. Stewart

Induced Coupled Plasma trace analysis exists but is not included yet.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

Spectrally pure: no calcite bands. Any calcite remaining after Na-acetate buffer treatment may affect the continuum only.

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2b3c4_ # SepSp-1.AcB # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns