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DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: HS138.3B, HS138.4B
MINERAL_TYPE: Oxide
MINERAL: Pyrolusite
FORMULA: MnO2
FORMULA_HTML: MnO2
COLLECTION_LOCALITY: Villa Grove, Colorado
ORIGINAL_DONOR: Hunt and Salisbury Collection
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
Trimorphous with Akhtenskite and Ramsdellite.
Grain size fractions are indicated by the extension after the sample number:
.1B = <5 µm
.2B = <74 µm
.3B = 74-250 µm
.4B = 250-1200 µm
IMAGE_OF_SAMPLE:
NO PHOTO
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
40 kV - 30 mA, 7.3-9.5 keV
File: mang138.out, -.mdi
References: JCPDS #24-735; Huebner's reference patterns; BUR-4120
Found: Pyrolusite, minor quartz, unidentified weak reflections at
4.2, 2.71, and 2.03 Angstroms
Sought but not found: Manganite, ramsdellite, romanechite, ranceite
Comment: Pyrolusite has broad peaks; the relative intensities do not agree with the JCPDS pattern or a pattern of synthetic pyrolusite. The pyrolusite is poorly crystallized. The 4.2 Angstroms reflection is in the position of the strongest groutite reflection (110), but the other two unidentified lines are not those of groutite.
J.S.Huebner, J. Pickrell, T. Schaefer, written communication (USGS)
Additional analysis: Pyrolusite (major), quartz (minor), goethite (trace), groutite (?), pyrite (?). Analysis by Steve Sutley
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EPMA, ICP(Trace), WChem
COMPOSITION_TRACE:
COMPOSITION_DISCUSSION:
Originally Hunt and Salisbury thought this sample was Manganite.
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1b2b3c4u # HS138.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns