Obsidian is brittle enough that it doesn't make decent axes/celts like some types of flint or chert can. I've seen a lot of bifaces like that near quarries along the Nevada/California border, the tan spots look like cortex from the outside of the obsidian chunk. If you found it isolated from a quarry, it was probably a combo tool/core. It could handle some cutting & scraping, and the flakes driven from the piece would have been used for cutting or flaked into points.
It could have been a hand chopper for just a short time. Like Joshua said Obsidian does not make very good axe making stone, it will shatter very easy. The artifact you have shows a fault in the stone in the last photo, it would have fell apart when struck on that end. They may have been making a tool and stopped when they found that on the inside of the stone or it could have been a one time use tool. The flakes would have made super sharp blades or points. Cool find
It was found before we got to an area where there was a lot of obsidian we were probalbly 2 or three hours north of the obsidian beds, We were eating lunch and this was the view.
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It was found before we got to an area where there was a lot of obsidian we were probalbly 2 or three hours north of the obsidian beds, We were eating lunch and this was the view.