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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: Dolomite HS102 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS102.1B, HS102.3B, HS102.4B

MINERAL_TYPE: Carbonate

MINERAL: Dolomite (Dolomite group)

FORMULA: CaMg(CO3)2

FORMULA_HTML: CaMg(CO3)2

COLLECTION_LOCALITY: Lee, MA

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION: .p> Forms series with Ankerite and with Kutnohorite.

"This is a recrystallized dolomitic marble, which displays the carbonate absorption features at longer wavelengths than typical for calcites. Weak absorption band at 1.0µm is due to ferrous iron, which is shown to be present at 0.03 wt.% in the sample."

Hunt, G.R., J.W. Salisbury, 1971, Visible and near-infrared spectra of minerals and rocks: II. Carbonates. Modern Geology, v. 2, p. 23-30.

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:
Photo of sample

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Dolomite plus trace of calcite XRD done by Norma Vergo

Clark, R.N., King, T.V.V., Klejwa, M., Swayze, G.A., and Vergo, N., 1990, High spectral resolution reflectance spectroscopy of minerals: Journal of Geophysical Research, v. 95, no. 8B, p 12,653-12,680. END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EPMA, ICP(Trace), WChem

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Bimodal grain size distribution:

population 1: average grain size = 288µm 98 vol%
population 2: average grain size = 15µm 2 vol%

average grain size of all populations: 285µm

Pure sample, sluggish fizz with dilute HCl. Lack of a vigorous fizz suggests very little if any calcite (this HCl mixture reacts vigorously with pure calcite samples). Uniaxial negative, high relief, higher order white, all consistent with dolomite. G. Swayze.

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2_3_4_ # Dolomite HS102.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1b2b3b4b # Dolomite HS102.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1b2_3_4_ # Dolomite HS102.4B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns