DK that is gorgeous. A lot like heat treated agate? I like the hinge from the basal thinning.
I'd call it a Dalvis. Or Cloton lol
Rick I found a site on the web where you can get some if you go to the folks that own a large portion of the quarry.
They like you to bring something in exchange. I have been to the Mandan Village where the Knife dumps into the Missouri and followed it way up stream I just didn't have the location for the quarry with me that day.
Zuma