Looks like it might be some sort of property marker. Is there a stake or post underneath it ?
Yes I see them now, so I am sticking with property (survey) markers. I have dug a few of these (on road widening projects). The only difference is that they had metal caps over the stake. Mine were probably more modern. My advice is to leave them where you found them Burburtia, just in case they are markers. If they are state markers, removing them can be a punishable fine according to the markings on the few I have found.Looks to be rebar stakes in the centers of both.