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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: Butlerite GDS25 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: GDS25

MINERAL_TYPE: Sulfate

MINERAL: Butlerite

FORMULA: Fe+3(SO4)(OH)*2H2O

FORMULA_HTML: Fe+3(SO4)(OH)•2H2O

COLLECTION_LOCALITY: MIT Collection

ORIGINAL_DONOR: Harvard Dana Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

This sample was originally called Fibroferrite (Dave Sherman). Fibroferrite and butlerite have almost the same composition, differing only in the H2O content.

IMAGE_OF_SAMPLE:
Photo of sample

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Pure butlerite.

Konnert, Judith and Marta Flohr, 1992, unpublished data, USGS Reston, VA.

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Avg. gr sz = 10 µm

Very pure sample, all fibrous grains, length fast, nearly straight extinction. Fibrous nature prevents further determination of optical properties. Since I have no optical data on this mineral type to test its identity I cannot be optically sure this is Fibroferrite. G. Swayze.

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1a2a3a4a # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns