The effects of void ratio and confinement stress on the response of a uniform, fine dune sand tested in triaxial compression with octahedral normal stress controlled is given in terms of a two-constant hyperbolic stress-strain formulation. Relations for both the initial tangent modulus and the ultimate shear strength of the sand are contained within the hyperbolic stress-strain relation. The ultimate shear strength as a function of void ratio and confinement stress is given by the mathematical limit of the hyperbolic stress-strain relation, and the initial tangent modulus is obtained by, differentiating the stress-strain equation with respect to strain and evaluation at zero strain.