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
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TITLE: Halloysite CM13 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: CM13 (also known as API13)

MINERAL_TYPE: Phyllosilicate

MINERAL: Halloysite (Kaolinite-Serpentine group)

FORMULA: Al2Si2O5(OH)4

FORMULA_HTML: Al₂Si₂O₅(OH)₄

COLLECTION_LOCALITY: Dragon Iron Mine, Eureka, Utah

ORIGINAL_DONOR: Clay Mineral Standard, Ward Natural Science Inc.

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Polymorphous with Dickite, Kaolinite, and Nacrite.

A spectrum for this sample was published by:

Clark, R.N., King, T.V.V., Klejwa, M., Swayze, G.A., and Vergo, N., 1990, High spectral resolution reflectance spectroscopy of minerals: Journal of Geophysical Research, v.g 95, no. 8B, p 12,653-12,680.

Who noted that the sample was spectrally pure.

IMAGE_OF_SAMPLE:
NO PHOTO

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Halloysite + quartz
less than 2µ 7A halloysite + smectite + trace 10A halloysite.
Spectrally pure. (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 46.3 wt% SiO₂

COMPOSITION: TiO2 0.11 wt% TiO₂

COMPOSITION: Al2O3 35.2 wt% Al₂O₃

COMPOSITION: Fe2O3 0.72 wt% Fe₂O₃

COMPOSITION: FeO 0.02 wt% FeO

COMPOSITION: MnO less than 0.02 wt% MnO

COMPOSITION: MgO 0.31 wt% MgO

COMPOSITION: CaO 0.31 wt% CaO

COMPOSITION: Na2O less than 0.15 wt% Na₂O

COMPOSITION: K2O less than 0.02 wt% K₂O

COMPOSITION: P2O5 0.26 wt% P₂O₅

COMPOSITION: H2O+ 14.4 wt% H₂O⁺

COMPOSITION: H2O- 1.80 wt% H₂O^-

COMPOSITION: H2O 16.2 wt% H₂O

COMPOSITION: LOI 15.8 wt% LOI

COMPOSITION: Total wt%

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

COMPOSITION: New Total wt%

COMPOSITION KEYWORD	Oxide ASCII	Amount	Weight Percent, %	Oxide html
COMPOSITION:	SiO2	46.3	wt%	SiO₂
COMPOSITION:	TiO2	0.11	wt%	TiO₂
COMPOSITION:	Al2O3	35.2	wt%	Al₂O₃
COMPOSITION:	Fe2O3	0.72	wt%	Fe₂O₃
COMPOSITION:	FeO	0.02	wt%	FeO
COMPOSITION:	MnO	less than 0.02	wt%	MnO
COMPOSITION:	MgO	0.31	wt%	MgO
COMPOSITION:	CaO	0.31	wt%	CaO
COMPOSITION:	Na2O	less than 0.15	wt%	Na₂O
COMPOSITION:	K2O	less than 0.02	wt%	K₂O
COMPOSITION:	P2O5	0.26	wt%	P₂O₅
COMPOSITION:	H2O+	14.4	wt%	H₂O⁺
COMPOSITION:	H2O-	1.80	wt%	H₂O^-
COMPOSITION:	H2O	16.2	wt%	H₂O
COMPOSITION:	LOI	15.8	wt%	LOI
COMPOSITION:	Total		wt%
COMPOSITION:	O=Cl,F,S		wt%	#correction for Cl, F, S
COMPOSITION:	New Total		wt%

COMPOSITION_TRACE:

None

COMPOSITION_DISCUSSION:

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

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

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Bimodal Grain Size Distribution:
mode 1: 670 µm @ 95 vol%
mode 2: 35 µm @ 5 vol%

avg. grain size = 650 µm

Sample is not isotropic under cross-polarized light. About 1 vol% of sample has iron-oxide staining. Larger grains are 50% coated with smaller grains. Because sample is not isotropic I think sample has other clay contaminants probably up to 50 vol%. G. Swayze.

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2b3b4b # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns