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 Salibury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Forms a serites 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. 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.

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: 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 av gr sz = 325 µm 99 vol%
population 2 av gr sz = 15 µm <1 vol%

av gr sz 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: 1_2_3_4_

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 ____ 0.2-3.0µm 200 g.s.=

LIB_SPECTRA: splib06a r ____ 1.5-25µm 250 g.s.=