Thick Walnut Plywood core?

Just opened some PG material including one sheet of thick walnut plywood and the core looks different then the medium hard maple. It’s not the fiberboard material and its not laminate layers. Anyone know what it is? I have only ordered thick Walnut and medium maple, so does all thick ply have this core?
It looks like an old 3/4" thick sheet material that I think was called block core, essentially blocks of wood glued up to be a core with 2 clean laminates for top and bottom. Great product, really stable and really heavy.


Only because you said pls.


@jbmanning5 pic is better then mine.

It actually looks like real wood, you can see some grain.
It looks like the same material that makes up the layers of piece of 1/4" underlayment or Luan sold at the big box stores, but its just one thickness instead of 3 (not including the 2 veneers).


Here is thick walnut on top of medium cherry on top of medium hard maple.


Not sure why I didn’t just take this pic in the first place. :face_with_raised_eyebrow: