Facts and Figures
name of sample	red clay
origin	commercially available from Argiletz, France
main constituents	biotite, illite, quartz
particle size	distributions measured with laser diffraction
	reff=1.5 micrometer, veff =1.6
particle shape	irregular (SEM image)
refractive index	estimated to be in the range:
	1.5-1.7 -  i0.001-0.00001
color	red brown powder
scattering matrix	from 5-173 degrees scattering angle
wavelength	441.6 nm (figure)
	632.8 nm (figure)
article	Scattering matrices of mineral particles at 441.6 nm and 632.8 nm.
	Volten H, Muñoz O, Rol E, de Haan JF, Vassen W, Hovenier JW,Muinonen K, Nousiainen T.
	Journal of Geophysical Research, 106, 17375-17401,2001