I used to think all those shiny black rocks on the beach were coal

I mean, I collected a bunch on the Oregon coast last summer thinking I had a cool haul. A geology student at the local visitor center told me they're actually basalt, and that coal is way less dense and would leave a mark. Has anyone else made this mix-up?

2 comments

2 Comments

hugo_craig119d ago

Did you try the mark test on your old haul?

martinez.karen9d ago

Yeah, about the mark test. I tried it on a few pieces from my last haul and honestly it was a total letdown. The marks rubbed off way too easy, like the ink wasn't even set right. It makes me question the whole batch now. I wouldn't trust it at all.