U.S. Geological Survey home page

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: Thuringite SMR-15 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: SMR-15.a, SMR-15.b, SMR-15.c, SMR-15.d

MINERAL_TYPE: Phyllosilicate

MINERAL: Thuringite (Chlorite Group)

FORMULA: (Mg,Fe)3(Si,Al)4O10(OH)2-(Mg,Fe)3(OH)6

FORMULA_HTML: (Mg,Fe)3(Si,Al)4O10(OH)2-(Mg,Fe)3(OH)6

COLLECTION_LOCALITY: Not available

ORIGINAL_DONOR: Gene Whitney, U.S.G.S

CURRENT_SAMPLE_LOCATION: U.S.G.S. Denver Spectroscopy Laboratory.

ULTIMATE_SAMPLE_LOCATION: U.S.G.S. Denver Spectroscopy Laboratory.

SAMPLE_DESCRIPTION:

Sample was ground in an alumina mortar and pestle and wet sieved with methanol into grain size fractions.

King, T.V.V. and R.N. Clark, 1989, Spectral Characteristics of Chlorites and Mg-Serpentines Using high-Resolution Reflectance Spectroscopy. Jour. Geophys. Res., 13.997-14,008.

Grain size fractions are indicated by the extension after the sample number:
.d = less than 30µm
.c = 30-45µm
.b = 60-104µm
.a = 104-150µm

IMAGE_OF_SAMPLE:
NO PHOTO

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Sample is representative of its structural classification. (King and Clark, 1989). END_XRD_ANALYSIS.

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

COMPOSITION
KEYWORD
Oxide
ASCII
Amount Weight
Percent, %
Oxide
html
COMPOSITION: SiO2 24.70 wt% SiO2
COMPOSITION: TiO2 0.69 wt% TiO2
COMPOSITION: Al2O3 21.10 wt% Al2O3
COMPOSITION: Fe2O3 37.50 wt% Fe2O3
COMPOSITION: MnO 0.72 wt% MnO
COMPOSITION: MgO 16.80 wt% MgO
COMPOSITION: CaO 0.40 wt% CaO
COMPOSITION: Na2O 0.32 wt% Na2O
COMPOSITION: K2O 0.03 wt% K2O
COMPOSITION: P2O5 0.30 wt% P2O5
COMPOSITION: LOI 7.50 wt% LOI
COMPOSITION: Total 101.00 wt%

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

Compositional data provided by Gene Whitney, USGS, Denver, CO

King, T.V.V. and R.N. Clark, 1989, Spectral Characteristics of Chlorites and Mg-Serpentines Using high-Resolution Reflectance Spectroscopy. Jour. Geophys. Res., 13.997-14,008.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Microscopically this appears to be pure thuringite. All size fractions were examined visually and by energy dispersive methods to ensure chemical homogeneity as a function of grain size interval.

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2b3c4_ # SMR-15.a # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1a2a3a4_ # SMR-15.b # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1_2a3a4_ # SMR-15.c # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1a2a3a4_ # SMR-15.d # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns