Is this petrified coal or obsidian?

[Bk007]

I found this in a river I need help to identify, it seems to have tree rings but it's very lightweight and soft but sharp

 

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[Indian Steve]

It looks more like coal to me. What area of the world was it found in?

 

[Bk007]

Northern Washington state, it looks like coal to me too but feels nothing like coal

 

[buck8point]

6 Different types of Coal.
https://www.coals2u.co.uk/blog/coal/the-many-different-types-of-coal

Id Say Anthracite

 

[Whiplash016]

Anthracite is my guess too