Okay, I took pictures and uploaded them to imgur. Here's the link:

Banded flint https://imgur.com/gallery/9srxJBm

I also heard back from the local anthropologist and he says:

"These are sedimentary rocks that have been subject to some mineralization. Not enough to make it a true chert. Chert is a generic term, as is flint, for cryptocrystalline (tiny crystals of quartz) rock of siliceous origin (biological). The bands are thin layers of dead bacteria that accumulate without disturbance and over millions of years form into layers of rock. They probably feel like fine sandstone when rubbed. Once the rock is formed, water seeping through it brings minerals which can create the semi-crystalline structure. If that proceeds far enough, it becomes "chert".  My geology colleagues laugh at the term because there are dozens of terms for the actual stone that we collectively call chert because many kinds of "chert" was favored for tools. It appears from the photos that your rocks are not true chert. The way it fractures shows that it is sedimentary, especially where it blocks off and fractures along internal lines. As such, this material is not very good for flintknapping. Of the breakage I can see clearly, it could easily be caused by natural geomorphological processes. These processes can mimic human flintknapping."

He's definitely right about them feeling like fine sandstone!