The mass formulas for finite lumps of strange quark matter with [ital u], [ital d], and [ital s] quarks and nonstrange quark matter consisting of [ital u] and [ital d] quarks are derived in a nonrelativistic potential model. The finite-size effects comprising the surface and curvature were consistently obtained, which shows a converging trend. It is found that there is a good possibility for the formation of metastable strangelets of large mass. The model predicts a low charge to mass ratio as the characteristic signature of strange matter in agreement with the relativistic studies. This study also yields an estimate for the bag energy density [ital B] in terms of the constituent quark mass and the baryon number density.