U.S. Geological Survey home page

USGS Spectral Library Version 7 Sample Description

Kokaly, R.F., Clark, R.N., Swayze, G.A., Livo, K.E., Hoefen, T.M., Pearson, N.C., Wise, R.A., Benzel, W.M., Lowers, H.A., Driscoll, R.L., and Klein, A.J., 2017, USGS Spectral Library Version 7: U.S. Geological Survey Data Series 1035, 61 p., https://doi.org/10.3133/ds1035
For more information on the library, see: local link web link

TITLE: Richterite HS336 Amphibole DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS336.1B, HS336.2B, HS336.3B, HS336.4B, HS336.6

MINERAL_TYPE: Inosilicate

MINERAL: Richterite (Amphibole group)

FORMULA: Na2Ca(Mg,Fe2+,Mn,Fe3+,Al)5(Si8O22)(OH,F)2

FORMULA_HTML: Na2Ca(Mg,Fe2+,Mn,Fe3+,Al)5(Si8O22)(OH,F)2

COLLECTION_LOCALITY: Sweden

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

"I-21 Richterite 336B--Sweden. Na2Ca(Mg, Fe2+, Mn, Fe3+, Al)5(Si8O22)(OH, F)2: This mineral occurs in thermally metamorphosed limestone's and skarns, and is also found as a hydrothermal product in veins in alkaline igneous rocks. This sample is contaminated with 30% magnetite, which reduces the overall reflectivity. It would also serve to quench the iron bands, were any displayed. However, the curve shown is for a sample cleaned of all magnetite, and it is still surprisingly free of electronic transition bands for an amphibole. The only well defined features are the 1.4µ OH band, which is clearly doubled, and the two OH bands near 2.32µ and 2.38µ."

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

IMAGE_OF_SAMPLE:
NO PHOTO

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Richterite (possibly fluoro-richterite) is major phase with diopside, mica, and at least one other trace mineral present. B. Benzel.

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_ # HS336.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # HS336.2B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2c3c4c # HS336.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # HS336.4B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # HS336.6 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns