Are the black and purple ones obsidian?
Yeah, even though there is no naturally occurring obsidian in Colorado. If you find it here, it's been hauled in/traded for....
I'll be darned, I've found lots of obsidian stuff in CO over the years and always just figured it was a locally sourced material. Seems like the old ones probably had a pretty vast trade network, probably lots bigger than they're given credit for.
