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:

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 talcs and pyrophyllites in the PDF2 database eliminates pyrophyllite-1A and one of the 2M talcs. 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, EM(WDS), ICP(Trace), WChem

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
talcs. That option was ignored for this sample. Average of six point analysis.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1_2_3_4_

LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment

LIB_SPECTRA: splib04a r 4698 0.2-3.0µm 200 g.s.=

LIB_SPECTRA: splib05a r ____ 0.2-3.0µm 200 g.s.=

LIB_SPECTRA: splib06a r ____ 1.5-25µm 250 g.s.=