DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS339

MINERAL_TYPE: Nesosilicate

MINERAL: Monticellite (Olivine group)

FORMULA: CaMgSiO4

FORMULA_HTML: CaMgSiO₄

COLLECTION_LOCALITY: Texas

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Forms series with Kirschsteinite.

Original spectrum published in: 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.

With the comment:"This sample is spectrally quite featureless except for a very weak band near 1.0µm and weak features in the visible. Although monticellite typically shows remarkably small departures from ideal composition, it is obvious that a small amount of Fe²⁺ has substituted for the Mg, producing both the 1µm band and the fall off toward the blue in the visible."

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 6.5-9.5 keV
References: JCPDS #35-590
Found: Monticellite; weak reflections at 5.6, 2.45, 1.56, 1.42 angstroms

Comment: Monticellite is well crystallized.

J.S.Huebner, J.Pickrell, T. Schaefer,written communication(USGS)

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

None.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

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 3111 0.2-3.0µm 200 g.s.=

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

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