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Clark et. al. 2003 USGS Open File Report 03-395
Spectral Library splib05a Sample Description

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

TITLE: Serpentine HS318 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS318

MINERAL_TYPE: Phyllosilicate

MINERAL: Serpentine

FORMULA: Mg3Si2O5(OH)4

FORMULA_HTML: Mg3Si2O5(OH)4

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:

"P-11 Serpentine 318B--Colorado. Mg3(Si2O5)- (OH)4: The principal occurrences of serpentine are those in which they are derived by alteration of ultrabasic rocks. Serpentine specimens, like talc, deviate little from the ideal composition. However, also like talc, small amounts of aluminum and iron may replace silicon and magnesium. This particular sample is burdened with magnetite contamination, but still displays ferric ion bands at 0.65 and 0.45µ as well as clearly visible OH features at 1.4µ and 2.34µ. This latter feature is attributed to a combination of the OH stretch with the Mg-OH bend."

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.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 6.5-9.5 keV
File: serpn318.out, -.mdi (edge/random mount)
References: SWBailey (1988, Clays and Clay Minerals 36, 193-213); FJWicks and DS O'Hanley (1988, MSA Reviews in Mineralogy 19, 91-167; JCPDS #11-386; Huebner's reference patterns.
Found: lizardite, minor chlorite, many unidentified but weak reflections

Comment: Excellent match to the JCPDS pattern. Strong pattern with some peak broadening. A member of Bailey's group C serpentines; probable 6T polytype of Wicks and O'Hanley, but with some discrepant intensities. The pattern is more complex than that of a 1T serpentine polytype.

J.S. Huebner, J. Pickrell, T. Schaefer, written communication(USGS)

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: 1c2_3_4_ # 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 4424 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 6189 0.2-3.0µm 200 g.s.=


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