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Clark et. al. 2003 USGS Open File Report 03-395
Spectral Library splib05a Sample Description

(For further information on spectrsocopy, see: http://speclab.cr.usgs.gov)

TITLE: Gibbsite WS214 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: WS214

MINERAL_TYPE: Hydroxide

MINERAL: Gibbsite

FORMULA: Al(OH)3

FORMULA_HTML: Al(OH)3

COLLECTION_LOCALITY: Minas Gerais, Brazil

ORIGINAL_DONOR: Ward Science Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Trimorphous with Bayerite and Nordstrandite.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Gibbsite - major component
Trace of unidentified residual.

Konnert, Judith and Marta Flohr, 1992, unpublished data, USGS Reston, VA.

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

average grain size= 30 µm

Ubiquitous light colored Fe-oxide ? staining. Sample looks pure otherwise; good cleavage, prismatic crystal habit, twinning, crystals too small for determine optical sign. Other optical properties are consistent with gibbsite. G. Swayze.

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment
LIB_SPECTRA: splib04a r 1749 0.2-3.0µm 200 g.s.= 30 µm
LIB_SPECTRA: splib05a r 2804 0.2-3.0µm 200 g.s.=


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