What do you think

[Bmerck]

The brown i was thinking flint or chert and the black maybe hammer stone or some kinda axe idk if the little line of brown means anything ?

 

[Haldean]

That black one looks like it may have been caught in a creek pothole. From what I understand a rock like that will get caught in a pothole and when the water level gets up the current will spin the rock round and round making the pothole perfectly round and making the rock smooth like that. Saw that on a gold mining video on here. The large potholes seemed to hold gold if any is in that area.