Thanks OD and tamrock! In the second set of pics, the top item seems to have a red center that goes all the way through. My thought was that it is bone marrow, or maybe a section of a longer tooth or horn.
I also see the resemblance to gastrolith on the second item, however when handling it I'm 99.9% sure that item is not stone. It doesn't have any weight. Perhaps petrified poop?