TITLE: Sepiolite SepSp-1 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: SepSp-1 (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.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Sepiolite plus calcite (Norma Vergo).

Spectrally pure: no calcite bands. Calcite affects the continuum only; confirmed by Na-acetate buffer purification (Norma Vergo).

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: XRF # XRF, EM(WDS), ICP(Trace), WChem


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 <0.02 wt% MnO
COMPOSITION: MgO 22.3 wt% MgO
COMPOSITION: CaO 1.07 wt% CaO
COMPOSITION: Na2O <0.15 wt% Na2O
COMPOSITION: K2O 0.20 wt% K2O
COMPOSITION: P2O5 <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:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1_2_3_4_

LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment

LIB_SPECTRA: splib04a r 4402 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib04a r 4413 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.=