n	Refractive index of pore liquid
P	Mass fraction of fluid
w	Oil content of transparent soil
${\alpha }_v$	Compression coefficient
$e_0$	Pore ratio
$C_c$	Compression Index
$E_s$	Compression modulus
$C_s$	Rebound Index
c	Cohesion
φ	Internal friction angle
m 1	Mass of the pore–fluid mixture
m 2	Mass of the fused-quartz sand particles
m 3	Mass of the nano-fumed silica powder
$n_{12}$	Refractive index of mixed pore fluid
$n_1$	Refractive index of individual fluid 1
$n_2$	Refractive index of individual fluid 2
$P_1$	Component mass fraction of fluid 1
$P_2$	Component mass fraction of fluid 2