Are these rocks safe for my aquarium

[Scorpio99]

I collected these rocks near a beach area, can anyone tell if these rocks are safe to use in my aquarium and how to provide simple treatment to make it safe

 

[twentyleagues]

Look like granite..... Put a light acid like vinegar on it and see if it reacts.

 

[Scorpio99]

Look like granite..... Put a light acid like vinegar on it and see if it reacts.

What sort of a reaction should I be looking for

 

[Rocksor]

bubbling

Also test the ph of the water that it is sitting in.

 

[Reiner]

Granite
depending on how clean the collection sight was you can run them under hot water and put a stiff brush to it and you should be good to go

 

[Reiner]

don't use the rock on the right since it looks rusty. Must have a high iron content. if it's just dirt that washes off you are good to go