  A discrete time crystal (DTC) is a robust phase of driven systems that breaks
the discrete time translation symmetry of the driving Hamiltonian. Recent
experiments have observed DTC signatures in two distinct systems. Here we show
nuclear magnetic resonance (NMR) observations of DTC signatures in a third,
strikingly different system: an ordered spatial crystal. We use a novel DTC
echo experiment to probe the coherence of the driven system. Finally, we show
that interactions during the pulse of the DTC sequence contribute to the decay
of the signal, complicating attempts to measure the intrinsic lifetime of the
DTC.
