Clay, Montmorillonite

Practical significance

Early choices of Earth spectral analogs showed a predominantly montmorillonite composition since its reflectance spectra in the VIS and NIR are similar to the Martian spectra (Toon et al. 1977)

Main constituent

Aluminium-rich clay mineral

Color

Light gray

Particle size Mie: reff (μm)

2.8

Particle size Mie: veff

1.2

Particle size Fraunhofer: reff (μm)

1.8

Particle size Fraunhofer: veff

1.6

Size distribution plot:

Size distribution table

size_montmorillonite.txt

Particle shape

Irregular

SEM/TEM images:

All SEM/TEM images (zip file)

Montmorillonite SEM images

Scattering matrix (1) wavelength in nm

488.00 nm

Scattering matrix (1) table

matrix_montmorillonite_488nm.txt

Scattering matrix (1) plot:

Scattering matrix elements Montmorillonite - 488 nm

Synthetic scattering matrix (1) wavelength in nm

488.00nm

Synthetic scattering matrix (1) table M

extra_montmorillonite_488nm_M.txt

Synthetic scattering matrix (1) table F

extra_montmorillonite_488nm_F.txt

Refractive index

1.52 + i0.0001 (488nm) (Sokolik and Toon 1999)

Angle range (deg)

[3,177]

Reference/s

Dabrowska et al., 2015