High energy density ($eps$) and temperature (T) links general relativity and hydrodynamics leading to a lower bound for the ratio of shear viscosity ($eta$) and entropy density ($s$). We get the interesting result that the bound is saturated in the s
imple model for quark matter that we use for strange stars at the surface for $T sim 80 MeV$. At this $T$ we have the possibility of cosmic separation of phases. At the surface of the star where the pressure is zero - the density $eps$ has a fixed value for all stars of various masses with correspondingly varying central energy density $eps_c$. Inside the star where this density is higher, the ratio of $eta/s$ is larger and are like the known results found for perturbative QCD. This serves as a check of our calculation. The deconfined quarks at the surface of the strange star at $T = 80 MeV$ seem to constitute the most perfect interacting fluid permitted by nature.
