Sanded grout used by mistake with marble
We have used sanded grout with marble tiles by mistake, will that cause any problems later other than scratching the marble tiles?
I read something about "you won't be able to polish it later if you used sanded grout", do you know something about that?
I also want to ask if the polished marble tiles have some spots that seem to be unpolished or slightly lower in level than the entire tile, would that mean it's a low grade marble or something?
Appreciate your help