Most of it looks like porcelain, except perhaps the tub surround.

Don't worry, call it tile and pray. Nobody wants it.......: )

Scratch at it with a knife in an unobtrusive spot. If you see the scratch, it's marble

It's marble.

Looks like marblle to me but why make a mistake by naming it at all just say tile and admit you do not know .MY guess woudl be that bathroom will be a gut job no matter what that is

It's marble.

It looks like marble to me (although, certain photo angles make it look a bit like porcelain) - but as has already been commented above, it seems very likely that the bathroom will be renovated by a new owner - so, maybe it doesn't matter?

Advertising it as "marble" doesn't really add anything to selling the house. If it was a nice new (or timeless) marble bathroom, it would add something for people who like/love marble - but there are also many people who dislike marble (especially based upon the many negative comments I've read on Houzz).

It probably is better to just not identify whether it's marble or porcelain IMHO - because regardless of what the material is, I'd be planning on removing it once I moved into the house.

I’ll add my “looks like marble.” Also, I liked Dani’s post above which seems like good advice.

It's marble, with a terrible setting job, bad grout choice, and a lot of wear and tear.

Call it marble; somebody will for sure want it. And imo there will be a better chance of that if they have the grout cleaned or regrouted - plus, lose the grey walls. Grey is over - in general; but the grey walls with this marble setup and flooring is garish. Also stage the house with some new light fixtures, if what is there is not classic or up to date.

Yes, It's marble and would look 1,000% better if someone took the time to clean the grout lines. Zep Grout Cleaner and Whitener can be purchased at the local HD.