Honestly? This is his problem to fix. What a jerk.

You have no idea. I am FUMING! It is his problem, but it's my house. These people have absolutely no regard. I dropped more than a few F bombs today! ;)

He needs to use a poultice...but it may dissipate on its own.

I would not try replacing them...trust me, the lights won't work if they do!!

Nancy

A poultice should work. Stains tend to naturally fade over time on marble too.

What a jerk! I would have him try to get the stain out.

if the pumice doesn't work, the guy just bought you a new floor.

I can't believe the installer did that!

He should fix it of course, and it probably won't need to be replaced. Most marble is pretty stain resistant. Maybe that's why he left it. But still!! Talk about not caring about your work!

Perhaps he expects it to come off after grouting when that gets cleaned up and he didn't expect anyone to critique the midway point in the job? Whatever. This really looks bad but you just need to talk with him and see what his plan is.

Good luck!

Remembered this thread today and am adding my sympathies. DH and I went to see a house yesterday which was recently restored by a GC we're considering hiring. I walked around the spankin' new kitchen counting the coffee rings in the marble left by the sloppy installer's (or some worker's) cup and was incensed by the carelessness.

I hope your guy will either make it right or replace it.

Don't replace the marble.
The stain can be corrected. There are several ways to do this. Is the marble honed or polished -looks honed in the pic. Coffee can be acidic so make sure it isn't an etch mark as well.
Best thing to do is hire a stone refinisher and bill it back to the contractor. I don't see why you would want to do it.
Don't give yourself a heart attack over it either.
If you have to do it your self here are some methods.
Using hydrogen peroxide (not the one in your medicine chest that 3% volume)you will need 30-40% volume hydrogen peroxide. Mix using flour, diatomaceous earth or baby powder unscented into a paste and place over the stains. Cover with plastic and let sit for six hours or so.
remove the plastic and don't touch until dry. Then remove it all and see what you get.
Another way is using a store bought poultice and applying that. You can also put down some paper towels about eight to ten sheets pad and place some bleach on top of it.
Let it sit on the stain for about an hour and then lift up and rinse well. You can dilute the bleach if you like. It wont damage the stone either way.

I assume payment has been withheld?