Pausanias describes the omphalos at Delphi as the navel-marker of that sanctuary. A named cult stone of the periegesis, not Lia Fáil and not the Stone of Scone.
Pausanias reports the omphalos at Delphi as Apollo’s navel-stone. A named stone of that god, not Benben, not the Delphic tripod, and not generic stone.