Bone ID and fossilization confirmation

[Willylock]

These objects appear to be fossilized bones.  Tongue test: (yuck) ahh seems sticky.  Lighter test: does not burn.  

What are some other tests I can do from home to confirm these are 1. Bones 2. Fossilized?  The objects are heavily mineralized.  Examining the objects several of the larger objects have a circular protrusion harder and sharp in their top middle and bottom middle.  The material protruding nipple appears to be more heavily mineralized than the majority of surface material.  
If these are bones can anyone identify them?

 

Found in western Pennsylvania in an upland area eroding out of a hill into a stream.  The stream is a headwater of the Potomac River.  A Bovid astragalus was also found within inches (the astragalus dies not appear to be fossilized).  In total 15 possible petrified bones were found on the surface within 1 meter of each other.  In the center of the objects was a large flat rectangular block of limestone.  
My uninformed supposition is this was a fire pit and bone marrow extraction spot over 10,000 years ago.  I’m looking for confirmation the large objects are indeed fossilized bones.  If they are I will seek advice about carbon dating. 

 

 

   

 

 

   

 

 

  

 

 

  

 

 

  

 

 

[Fossildude19]

The only bone I am seeing is the astragalus, which you posted earlier. 

The other ones are suggestively shaped rocks. 

[Willylock]

They very well may be rocks.  hope not 

[Willylock]

What is the standard for identifying petrified bones?  Is a microscopic image definitive? What is the best preparation process?