Cedar Rapids/Cedar River rock

[paulc]

So I am visiting family here in Cedar Rapids, spent some time walking along the river and I pulled 3 rocks that looked maybe knapable. 
These two seem to flake okay without having any tools except a random stone to strike with.  Anyone knap any rock from the Cedar River?

Thoughts on what i have?  I will take these two pieces home, and maybe look a bit some more tomorrow before flying out.  And is it legal to collect along Cedar River?

Thanks, Paul

[bjrogg]

Sorry I can’t answer any of your questions, but I think it looks very promising.

Bjrogg

[Parnell]

Cool looking rock.  You make any progress on it? 

[paulc]

I was able to make sharp gravel out of the grey banded piece...got a mix of flake and shatter when I hit it.  Both are pretty hard so don't flake real well without a good strong wind-up...doesn't help the accuracy of my strikes!  Played a little with indirect but I have never been able to get any real success with indirect with quality stone so....I still have some pieces large enough to not put under foot just yet...I will continue to try and get some results with indirect.  Paul

[JackCrafty]

Looks like "man rock". Heat treat or get beat.

[TRACY]

Looks like it will need some heat but is still knappable!