The fascinating interplay between topology and magnetism was first observed in integer spin chains. As conjectured by Haldane, half-integer and integer spin chains differ in their excitation spectra: while the former are gapless, the latter contain a Haldane gap. Though there are now many examples of Haldane gap materials, they all contain spin chains and are thus quasi-one-dimensional materials. Recent proposals suggest that strongly correlated, three-dimensional spin-one diamond lattices can also harbor topological magnetic states and Haldane-gapped excitation spectra, however, no materials have been found to harbor spin-one on a diamond lattice thus far. The authors present data on NiRhO, a tetragonal spinel with Ni (S= 1) on a diamond lattice, and present it as a candidate three-dimensional topological paramagnet.