Rocks help

[Florio]

Hey guys I found a rock in my yard I want to put in my tank, I did the vinegar and boiled it

With no issues. My only concern is it is a little brown In spots. I cannot tell if it is rust or if its just the rock, I scrubbed it for a good while did not manage to get it off

What do you guys think, safe or no?

( the green stuff is not green in real life )

[jcolon]

That's probably just weathering that's giving the rock those brown patches.

[MMantelli]

As long as there's no metallic looking veigns or layers in it u should be fine I have rocks in my tank I've found from cali to Florida and everyone is happy happy