Cordierite-QtzMus

Spectrum Details

Modality

NIR

Category

soil

Material Type

Intimate

Sample ID

HS346.1B, HS346.2B, HS346.3B, HS346.4B

Collection Locality

Guffy, Colorado

Spectral Purity

1c2_3_4_ # HS346.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1c2_3_4_ # HS346.2B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1c2c3c4c # HS346.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1c2_3_4_ # HS346.4B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

Composition / XRD

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

Sample Description

Forms series with Sekaninaite. Dimorphous with Indialite. "C-2 Cordierite 346B--Guffy, Co . Al3(Mg, Fe^2+)2 (Si5Al018): Cordierite is a mineral of metamorphic origin usually found in gneisses and crystalline schists, or in contact metamorphic zones. Its spectrum shows a weak Fe^2+ feature at 0.95 µ, which is in accord with typical cordierite composition, and weak broad hydroxyl and water features at 1.4, 1.9, and 2.2 µ which are not. These latter bands are due to alteration products, principally muscovite. Reflectivities I through IV are 50%, 43%, 31%, and 12% at 1.0 µ." 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. IMAGE_OF_SAMPLE:

XRD Analysis

Cordierite + quartz + muscovite + talc (Norma Vergo)

X Units

cm⁻¹

Y Units

Absorbance

Data Points

2,126