  Quantum discord is usually referred to as a measure for quantum correlations.
In the search of the fundamental resource to gain a quantum advantage in
quantum information applications, quantum discord is considered a promising
candidate. In this paper we present an alternative view on quantum correlations
in terms of the rank of the correlation matrix as introduced by Dakic, Vedral,
and Brukner [Phys. Rev. Lett. 105, 190502 (2010)]. According to our analysis,
information about the quantum discord does not necessarily determine the amount
of quantum correlations but rather the quantumness of the state. Nonzero
quantum discord is only a necessary but not a sufficient condition for
correlations above the classically achievable limit. This becomes clear when we
consider states of nonzero discord, which can be created from zero discord
states only by a single local operation. We further show that the set of these
states has measure zero.
