Southern Illinois ohio river rock I.D

[whistler84]

Hi all, i wanted to get my sons involved in some hands on activities outdoors, so i decided on rock tumbling. I have a small ditch at the rear of my property, its filled with all sorts of sizes of the main rock i have pictured. I cant really lay an I.D on it. I have included pictures of the area and some finished polished stones to show how much variety comes from them. , any help would be great!

 

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[fuss]

The blocky shape resembles calcite or a feldspar, see if you can leave a scratch mark on it with a knife, interesting looking stuff.

 

[DDancer]

It polishes up very well so its pretty hard. What I'm seeing looks to be massive quartz in what looks like a mixed variety of types. Chalcedony, jaspers and agate like banding. There may be some feldspar in the mix giving it the blocky fracture look or it maybe due to micro crystallization of Pseudocubic quartz. Quartz is a fascinating material with a lot of variaties. That last picture looks like a nice block of fossilized shells.
Here is a link on Quartz you might find interesting, and below is an excerpt from it on Crystal habits of quartz : https://www.mindat.org/min-3337.html

e) Pseudocubic quartz (pseudocubic habit, cubic habit, cube quartz, "Würfelquarz"): Crystals with a dominant r or z form that look like slightly distorted cubes.

 

[whistler84]

Thanks guys. The variety boggles my eye, its alot to take in

 

[faribo]

possibly chert

 

[ToddsPoint]

Looks like a piece of Flintridge flint that the glacier pushed into the Ohio R. I know for certain there is glacial Flintridge at a place in SE IN. Gary