✅ SOLVED Big chert tool?

[Freemindedclark]

 

[ToddsPoint]

It looks like an igneous rock to me. The glacier brought a gazillion tons of rock like that to Iowa from Canada. Indians generally used dark colored rocks (mafic rocks) for celts and axes and avoided lighter colored (felsic) rocks as they are not near as hard. Gary

 

[arrow86]

Looks natural to me

 

[Tnmountains]

Is is natural and here is how you tell. The last pictures posted shows inclusions in the stone. If it was a mortar for grinding or breaking nuts they would not put a cupulet near the edge as it would beak the mortar. Also most mortars or a lot will have the cups on both sides.
That was one that needed a further look. Hope this helped some.
HH

 

[The Grim Reaper]

Not Chert and not a Tool.

 

[Freemindedclark]

Thanks for the help all.