  We present a new set of inseparabilty inequalities to detect entanglement in
$N$-spin states. These are based on negative partial transposition and involve
collective spin-spin correlations of any two partitions of the entire system.
They also reveal the rich texture of partial separability for different
partition and can discriminate between GHZ-type and W-type entanglement, as
well. We introduce a new concept of relative entanglement of two different
systems and two different partitions in a spin-ensemble. These criteria can be
applicable to non-symmetric states and states with odd or even $N$.
