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Konnert, Judith and Marta Flohr, 1992, unpublished data, USGS Reston, VA.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

avg gr sz = 30 µm

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

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 1749 0.2-3.0µm 200 g.s.= 30 µm

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

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