[en] Using a generalized internal symmetry group analogous to the Lorentz group, we have constructed a covariant n²-plet mass operator. This operator is built as a scalar matrix in the (n;n*) representation, and its SU(n) breaking parameters are identified as intrinsic boost ones. Its basic properties are: covariance, Hermiticity, positivity, charge conjugation, quark contents, and a self-consistent n²-1, 1 mixing. The GMO and the Okubo formulas are obtained by considering two different limits of the same generalized mass formula