  We define and study kinematical observables involving fermion spin, such as
the total spin of a collection of particles, in loop quantum gravity. Due to
the requirement of gauge invariance, the relevant quantum states contain strong
entanglement between gravity and fermionic degrees of freedom. Interestingly we
find that properties and spectra of the observables are nevertheless similar to
their counterparts from quantum mechanics. However, there are also new effects.
Due to the entanglement between gravity and fermionic degrees of freedom,
alignment of quantum spins has consequences for quantized geometry. We sketch a
particular effect of this kind that may in principle be observable.
