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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: Hematite WS161 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: WS161

MINERAL_TYPE: Oxide

MINERAL: Hematite (Hematite group)

FORMULA: alpha-Fe2O3

FORMULA_HTML: alpha-Fe2O3

COLLECTION_LOCALITY: Cleator Moor, Cumberland, England

ORIGINAL_DONOR: Ward Science Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Dimorphous with Maghemite.

IMAGE_OF_SAMPLE:
Photo of sample

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Comments: Using quartz (100), (101), (112), and (211) reflections as an internal standard for 2 theta, 11 hematite reflections were refined to obtain the cell dimensions a=5.035(1), and b=13.745(4) Angstroms. Within the limits of error given above (1 sigma), these dimensions are those of pure Fe2O3 (see PDF2 33-0664).

File: hemat161.mdi, *.out
References: Huebner's reference patterns
Found: Hematite, minor quartz

Comment: Strong, sharp, symmetric hematite reflections indicate excellent crystallinity and suggest compositional heterogeneity. Likewise, the quartz is well crystallized. Hematite peak positions are consistent with Fe2O3 composition.

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EPMA, ICP(Trace), WChem

COMPOSITION_TRACE:

None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

mode:
80 vol% hematite
20 vol% quartz

average grain size = 6 µm

Sample is extremely fine grained but contains significant quartz? contamination. 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