Clark and others 2007 USGS Data Series 231
Spectral Library splib06a Sample Description

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

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:

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Konnert, Judith and Marta Flohr, 1992, unpublished data, USGS Reston, VA.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, EM(WDS), 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

LIB_SPECTRA_HED:	where	Wave Range	Av_Rs_Pwr	Comment
LIB_SPECTRA:	splib04a r 765	0.2-3.0µm	200	g.s.= 10 µm
LIB_SPECTRA:	splib05a r 1439	0.2-3.0µm	200	g.s.=
LIB_SPECTRA:	splib06a r 3947			g.s.=
LIB_SPECTRA:	splib06a r 3959			g.s.=