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: Talc WS659 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: WS659

MINERAL_TYPE: Phyllosilicate

MINERAL: Talc

FORMULA: Mg3Si4O10(OH)2

FORMULA_HTML: Mg₃Si₄O₁₀(OH)₂

COLLECTION_LOCALITY: Fowler, New York

ORIGINAL_DONOR: Ward Natural Science Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

IMAGE_OF_SAMPLE:

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV- 30 mA, 6.5-9.5 keV
File: talc659.mdi
References: PDF2# 12-0203, 13-0558, 19-0770, 25-0022, 29-1493; Huebner's reference patterns
Found: 2:1 layer silicate (pyrophyllite or talc)

Comments: Intense, narrow basal reflections with excellent resolution of the alpha1-alpha2 components. Non-basal reflections are few, weak, and broad. There is severe preferred orientation; line-based search match is unsuccessful. The only likely phase returned by profile-based search-match is pyrophyllite (12-0203). Visual comparison of WS-659 with the five talc's and pyrophyllites in the PDF2 database eliminates pyrophyllite-1A and one of the 2M talc's. Remaining are 2M1 pyrophyllite (12-0203) and 2M talc (13-0558, 19-0770). WS-659 adequately matches those pyrophyllite reflections with large miller indices l and small or zero h and/or k. Shoulders close to 8.6 and 3.33 Angstroms are not explained.

END_XRD_ANALYSIS.

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

COMPOSITION
KEYWORD Oxide
ASCII Amount Weight
Percent, % Oxide
html

COMPOSITION: SiO2 58.38 wt% SiO₂

COMPOSITION: TiO2 0.03 wt% TiO₂

COMPOSITION: Al2O3 0.18 wt% Al₂O₃

COMPOSITION: FeO 0.22 wt% FeO

COMPOSITION: MnO 0.56 wt% MnO

COMPOSITION: MgO 31.90 wt% MgO

COMPOSITION: ZnO 0.03 wt% ZnO

COMPOSITION: BaO 0.00 wt% BaO

COMPOSITION: CaO 0.65 wt% CaO

COMPOSITION: Na2O 0.17 wt% Na₂O

COMPOSITION: K2O 0.01 wt% K₂O

COMPOSITION: Cl 0.01 wt% Cl

COMPOSITION: F 0.25 wt% F

COMPOSITION: Total 92.29 wt%

COMPOSITION KEYWORD	Oxide ASCII	Amount	Weight Percent, %	Oxide html
COMPOSITION:	SiO2	58.38	wt%	SiO₂
COMPOSITION:	TiO2	0.03	wt%	TiO₂
COMPOSITION:	Al2O3	0.18	wt%	Al₂O₃
COMPOSITION:	FeO	0.22	wt%	FeO
COMPOSITION:	MnO	0.56	wt%	MnO
COMPOSITION:	MgO	31.90	wt%	MgO
COMPOSITION:	ZnO	0.03	wt%	ZnO
COMPOSITION:	BaO	0.00	wt%	BaO
COMPOSITION:	CaO	0.65	wt%	CaO
COMPOSITION:	Na2O	0.17	wt%	Na₂O
COMPOSITION:	K2O	0.01	wt%	K₂O
COMPOSITION:	Cl	0.01	wt%	Cl
COMPOSITION:	F	0.25	wt%	F
COMPOSITION:	Total	92.29	wt%

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

Tom's Fe⁺² Fe⁺³ program made all Fe as Fe⁺³ unlikely for
talc's. That option was ignored for this sample. Average of six point analysis.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

Spectral features are similar to those of XRD verified tl2702 and HS21 talc samples.

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2b3b4b WS659 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns