Anybody know how this was formed?

[notarocknerd]

Found this in Colorado and am just amazed by it.

The "cannon ball" part is apx. 14 inches dia and the larger "ball" it broke out of is close to two feet dia.

Some sort of sandstone creation. Just curious how common this is and what it is called/how it was made.

Any help would be appreciated.

Thanks in advance, ML

 

[Bajahunter]

It is called a concretion. Fairly common. Found in sedimentary rock.
https://www.desertusa.com/desert-minerals/concretions.html