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
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:
Montmorillonite size distribution
Size distribution table
Particle shape

Irregular

Color
Light gray
SEM/TEM images:
Montmorillonite SEM image
All SEM/TEM images (zip file)
Scattering matrix (1) wavelength in nm
488.00 nm
Scattering matrix (1) table
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
Synthetic scattering matrix (1) table F
Refractive index

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

Angle range (deg)
[3,177]