  Nuclear Magnetic Resonance (NMR) spans diverse fields from biology to quantum
science. Employing NMR on a floating object could unveil novel possibilities
beyond conventional operational paradigms. Here, we observe Nuclear Magnetic
Resonance (NMR) within a levitating micro-diamond using the nuclear spins of
nitrogen-14 atoms. By tightly confining the angular degrees of freedom of the
diamond in a Paul trap, we achieve efficient hyperfine interaction between
optically polarized electronic spins of nitrogen-vacancy centers and the
$^{14}$N nuclear spin, enabling nuclear spin polarization and quantum state
read-out revealing coherence times up to hundreds of microseconds. This
represents the longest recorded spin coherence time in a levitated system,
surpassing previous records by three orders of magnitude. Our results offer
promise for various applications, including cooling macroscopic particles to
their motional ground state and exploring geometric phases for gyroscopy.
