U.S. Geological Survey home page


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: Datolite SU51399 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: SU51399

MINERAL_TYPE: Nesosilicate

MINERAL: Datolite

FORMULA: CaBSiO4(OH)

FORMULA_HTML: CaBSiO4(OH)

COLLECTION_LOCALITY: None

ORIGINAL_DONOR: None

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

None

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 6.5-9.5 keV
File: dat51399_mdi, *.out (smear mount on quartz plate)
References: JCPDS #36-429
Found: Datolite, unindexed very weak reflections at 3.03 and 1.838 angstroms

Comment: The very weak reflections may be datolite reflections that are too weak to be listed by JCPDS. Reflections are very sharp, suggesting excellent crystallinity.

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE: None

None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Mode:
95 vol.% Datolite
5 vol.% Calcite

Bimodal Grain size distribution:
population:1 size = 237 µm at 80 vol%
population:2 size = 15 µm at 20 vol%

average grain size = 210 µm

Biaxial (-), no cleavage, conchoidal fracture, consistent with Datolite. Difficult to optically differentiate Datolite from calcite under microscope. Vol% calcite estimated from number of grains that fizzed with HCl. 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 1344 0.2-3.0µm 200 g.s.= 210 µm
LIB_SPECTRA: splib05a r 2320 0.2-3.0µm 200 g.s.=


USA.gov logo  Take Pride in America button