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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: Nephrite HS296 Amphibole DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS296

MINERAL_TYPE: Inosilicate

MINERAL: Nephrite (Jade)(Actinolite)(Amphibole group)

FORMULA: Ca2(Mg,Fe+2)5Si8O22(OH)2

FORMULA_HTML: Ca2(Mg,Fe+2)5Si8O22(OH)2

COLLECTION_LOCALITY: British Columbia

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

"I-19 Nephrite 296B--British Columbia: Nephrite is a tough compact variety of either tremolite or actinolite, which is used as the second source of gem quality jade (see inosilicate, I-9 for other source, jadeite). This sample contains magnetite as an impurity, which contributes to its low reflectivity, but the ferric and ferrous features are still apparent at 0.7µ and 1.0µ, as is the accompanying fall off to the blue. The hydroxyl features are quite evident at 1.4µ and 2.33µ with a small feature at 1.9µ indicating including water."

Sieve interval 74 - 250µm.

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: neph296.out, -.mdi
References: JCPDS # 13-347; Huebner's reference patterns
Found: chlorite, Ca-amphibole, unindexed weak reflection at 1.804 angstroms.

Comment: Some strong chlorite basal intensities present, but the (001) and (003) are weak. Fairly well crystallized tremolite is observed with a very good match to the JCPDS pattern.

J.S.Huebner, J. Pickrell, T. Schaefer, written communication(USGS 1994)

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None

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 3462 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 4927 0.2-3.0µm 200 g.s.=


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