Elements with the hexagonal close-packed crystal structure (packing layers only) include
Be, Mg, Ca, Sr, Sc, Y, Ti, Zr, Hf, Tc, Re, Ru, Os, Co, Zn, Cd, and Tl.
Many structures can be viewed as hexagonal close-packed layers with occupied tetrahedral or octahedral holes between layers:
Pa Tb Oc Ta Pb Ta Oc Tb Pa