U.S. Geological Survey home page


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: Tremolite HS18 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS18

MINERAL_TYPE: Inosilicate

MINERAL: Tremolite (Amphibole group)

FORMULA: Ca2Mg5Si8O22(OH)2

FORMULA_HTML: Ca2Mg5Si8O22(OH)2

COLLECTION_LOCALITY: St. Lawrence County, New York

ORIGINAL_DONOR: Hunt and Salibury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Forms series with Actinolite and Ferroactinolite.

"S-1A. Amphibole, variety Tremolite. St. Lawrence Co., N.Y. (18B). This sample has a fairly prominent broad band near 1µ, indicating that it contains some ferrous ion. It displays a very sharp band at 1.4µ, and less sharp bands between 2.0 and 2.5 µ due to the overtone and combination tones of the OH stretch, respectively. In particular, the bands at 2.2 and 2.3 µ are due to combination tones of the OH stretch with lattice modes. The weak band at 1.9µ is probably due to a small amount of molecular H2O in the sample."

Hunt, G.R., J.W. Salisbury, 1970, Visible and near-infrared spectra of minerals and rocks: I. Silicate minerals. Modern Geology, v. 1, p. 283-300.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Tremolite + medium amount quartz + small amount of mica + large amount of others; M: ~1% magnetite, no other minerals visible (Norma Vergo)

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 57.70 wt% SiO2
COMPOSITION: TiO2 0.05 wt% TiO2
COMPOSITION: Al2O3 1.00 wt% Al2O3
COMPOSITION: FeO 0.34 wt% FeO
COMPOSITION: MnO 0.33 wt% MnO
COMPOSITION: MgO 24.45 wt% MgO
COMPOSITION: CaO 12.26 wt% CaO
COMPOSITION: Na2O 0.51 wt% Na2O
COMPOSITION: K2O 0.15 wt% K2O
COMPOSITION: Total 97.79 wt%

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

Average of 6 analyses.
XFe+2 = 0.0083
XFe+3 = 0.0083
XMg+2 = 0.9924
XFetot = 0.0151

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 5033 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 6886 0.2-3.0µm 200 g.s.=


USA.gov logo  Take Pride in America button