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: Rhodonite HS325 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS325

MINERAL_TYPE: Inosilicate

MINERAL: Rhodonite

FORMULA: MnSiO3

FORMULA_HTML: MnSiO₃

COLLECTION_LOCALITY: Colorado

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

This sample contains very small amounts of magnetite, pyrolusite and calcite. The visible spectrum is dominated by features typical of Mn²⁺ transitions, displaying bands at 0.35 µ, 0.37 µ, 0.42 µ, and 0.55 µ, resulting in the characteristic pink color of this mineral. The strong broad band near 1.04 µ and 1.9 µ features are typical of molecular water, probably in fluid inclusions.

Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1973, Visible and near-infrared spectra of minerals and rocks: VI. Additional silicates. Modern Geology, v. 4, p. 85-106.

IMAGE_OF_SAMPLE:

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 7.3-9.5 keV
File: rhod325.mdi
References: Huebner's reference patterns; PDF2 #29-0985
Found: Pyroxmangite

Comments: Peaks are symmetric but not strong; alpha1-alpha2 are not resolved. The pattern has a high background caused by X-ray fluorescence (Mn- or Fe-rich composition is probable). HS-325 is very similar to Huebner's reference patterns for synthetic pyroxmangite of MnSiO3 composition (runs Hy-67 and run-130) and unlike that of rhodonite (run49; see Heubner, 1986). Profile based search-match returns pyroxmangite (PDF2 #29-0985) There are weak, very sharp reflections at 7.2 and 1.912 Angstroms but no mineral in the PDF2 database has two strong reflections at these positions.

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1c2c3b4_ # 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 4208	0.2-3.0µm	200	g.s.=
LIB_SPECTRA:	splib05a r 5914	0.2-3.0µm	200	g.s.=
LIB_SPECTRA:	splib06a r 19332			g.s.=
LIB_SPECTRA:	splib06a r 19344			g.s.=