DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: HS318.1B, HS318.2B, HS318.3B, HS318.4B, HS318.6
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.
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
.6 = cut slab
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
40 kV - 30 mA, 6.5-9.5 keV
File: serpn318.out, -.mdi (edge/random mount)
References: S.W. Bailey (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, EPMA, 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_ # HS318.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # HS318.2B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # HS318.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # HS318.4B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # HS318.6 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns