Monticellite

Spectrum Details

Modality

NIR

Category

mineral

Material Type

Nesosilicate

Sample ID

HS339.1B, HS339.2B, HS339.3B, HS339.4B

Collection Locality

Texas

Spectral Purity

1b2_3_4_ # HS339.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1b2_3_4_ # HS339.2B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1c2c3c4c # HS339.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1c2_3_4_ # HS339.4B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

Composition / XRD

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

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 Fe^2+ has substituted for the Mg, producing both the 1µm band and the fall off toward the blue in the visible." Grain size fractions are indicated by the extension after the sample number: .1B = IMAGE_OF_SAMPLE:

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)

X Units

cm⁻¹

Y Units

Absorbance

Data Points

2,126