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(For further information on spectroscopy, see:
http://speclab.cr.usgs.gov)
TITLE: Actinolite HS116 DESCRIPT
DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: HS116
MINERAL_TYPE: Inosilicate
MINERAL: Actinolite (Amphibole group)
FORMULA: Ca2(Mg,Fe+2)5Si8O22(OH)2
FORMULA_HTML: Ca2(Mg,Fe+2)5Si8O22(OH)2
COLLECTION_LOCALITY: San Bernadino, CA
ORIGINAL_DONOR: Hunt and Salisbury Collection
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
Forms a series with Tremolite and Ferro-actinolite.
Original spectrum published in:
Hunt, G.R., J.W. Salisbury, 1970, Visible and near-infrared spectra of minerals and rocks: I. Silicate minerals. Modern Geology, vol. 1, pp283-300.
With the note that this sample lacks the contamination by opaque inclusions that is seen in the actinolite sample HS22.
A spectrum of this sample is also published in:
Clark, R.N., T.V.V. King, M. Klejwa, G. Swayze, and N. Vergo, 1990, High spectral resolution reflectance spectroscopy of minerals: J. Geophys Res., v. 95, 12653-12680.
Where it is noted that, although XRD indicates chlorite but no chlorite bands are seen spectrally, microscope analysis indicated ~1% opaque and ~5 volume% chlorite as contaminants. The sample measured was HS116.3B, which was dry sieved to the grain-size interval 74-250 µm.
Analysis of cation proportions indicates that this actinolite is low enough in iron to border on being called a tremolite.
IMAGE_OF_SAMPLE:
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
Analysis by Norma Vergo indicates Actinolite + Chlorite
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: EM(WDS) # XRF, EM(WDS), ICP(Trace), WChem
| COMPOSITION KEYWORD |
Oxide ASCII |
Amount | Weight Percent, % |
Oxide html |
|---|---|---|---|---|
| COMPOSITION: | SiO2 | 57.78 | wt% | SiO2 |
| COMPOSITION: | TiO2 | 0.02 | wt% | TiO2 |
| COMPOSITION: | Al2O3 | 0.22 | wt% | Al2O3 |
| COMPOSITION: | Cr2O3 | 0.06 | wt% | Cr2O3 |
| COMPOSITION: | FeO | 4.38 | wt% | FeO |
| COMPOSITION: | MnO | 0.12 | wt% | MnO |
| COMPOSITION: | MgO | 22.39 | wt% | MgO |
| COMPOSITION: | CaO | 12.13 | wt% | CaO |
| COMPOSITION: | Na2O | 0.38 | wt% | Na2O |
| COMPOSITION: | K2O | 0.07 | wt% | K2O |
| COMPOSITION: | Total | 97.55 | wt% | |
| COMPOSITION: | O=Cl,F,S | wt% | #correction for Cl, F, S | |
| COMPOSITION: | New Total | wt% |
COMPOSITION_TRACE: None
COMPOSITION_DISCUSSION: EM analysis by Gregg A. Swayze at USGS Branch of Geophysics, Denver.
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
Clark, R.N., T.V.V. King, M. Klejwa, G. Swayze, and N. Vergo, 1990, High spectral resolution reflectance spectroscopy of minerals: J. Geophys Res. 12653-12680.
Bimodal grain size distribution:
population 1 avg. grain size= 325 µm 99 vol%
population 2 avg. grain size = 15 µm <1 vol%
avg. grain size for entire populations = 325 µm
Note the presence of ~1% opaque and ~5 volume% chlorite as inclusions. Actinolite prisms bounded by cleavage surfaces. G. Swayze
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1b2_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 28 | 0.2-3.0µm | 200 | g.s.=325µm |
| LIB_SPECTRA: | splib05a r 66 | 0.2-3.0µm | 200 | g.s.= |
| LIB_SPECTRA: | splib06a r 91 | g.s.= |