What rock is this? Quick reply please

[bcutajar]

What rock is this and does it effect pH or hardness i did vinegar test nothing happened

 

[Aquena]

I can't help you with the rock type, but could you tell me about the vinegar test? (How to do it, when, what to look for etc.) thanks!

I wonder if your rock is marble or has some quartz? I have no idea though.

 

[bcutajar]

Pretty much i poor some vinegar on and saw if it fizzed up which it did not so thats 1 sign its okay for tropical water