Thanks dedtired - I am happy to hear that you had a positive outcome from this! Did you use acetone from a hardware store as opposed to nail polish remover? Did you rub it on with a rag and wait a few minutes before rubbing it off? Did you wash it with some soapy water after you were finished?

Rupes, After you tested the lemon juice on the sealer did you try to remove it? I'm wondering if it'll be permanent or if it can be dealt with. When our honed AB counters were first installed we had quite a few "stains.". For example, grease splatters. I could not get them out. They have since disappeared...whether they were absorbed into the stone or what, I don't know. I do periodically use the Method cleaner so I'm wondering if that helped. What I do now to clean the counters is use hot water and a tiny bit of dish soap, then use the Method cleaner every few days or so, with a microfiber cloth. I haven't seen anything on our counters like what you showed with the test above, even though our marble counter has etched quite a bit. I've heard the Cambria Black is less prone to fingerprints,etc., if that's an option for you.

So should I request a new piece of stone or a different one? You don't know yet whether you don't have AB or not. Read the link I posted above called "How to tell if your granite is dyed". Follow the instructions on how to tell. Acetone can be purchased at HD. And, if you find out it's not real AB, it doesn't mean you have to switch it out. It means you have to care for it differently than AB. Read the article I posted above called "What to do if your granite is dyed". Should this be the stoneyard's responsibility? Again, read the articles I linked above. One mentions that often the stoneyard and/or fabricator have no idea that the stone is not AB. Your timeline doesn't make sense. "the marks were there after they used acetone". Why did they apply acetone to newly-installed counters? Are you sure it wasn't the first application of sealant, then perhaps they applied a second application of sealant? (I am guessing here) Again, I repeat, AB does not etch, and it does not need sealant because it is so dense. It is too dense for sealant to penetrate. The marks in the pics look like wipe marks, i.e. sealant was wiped on, and then it dried sitting on top of the surface, creating the haze in a wiping pattern. Again, as Littlesmokie and I said previously, this is easily solved by removing the sealant with acetone.

"I think they applied the sealer incorrectly." It may have not needed sealer at all. If the stone is too dense to absorb the sealant - as most black granites are - the sealant sits on top of the stone, forming a haze. This is particularly noticeable if a dish or something is pulled across the counter, streaking the sealant. There are many granites that do not ever need to be sealed because they are too dense, but unfortunately, many fabricators apply sealant habitually, whether the granite needs it or not. The sealant can be removed with acetone. If you have some nail polish remover in the house, you can try that, since nail polish remover is acetone. Otherwise you can get acetone at Home Depot or hardware stores. A little goes a long way. It would be best to test an inconspicuous spot with the acetone, and wipe off, and see what happens. I say inconspicuos spot because there are some black granites being sold that have been dyed to be more black than they originally were. If that is the case with yours, then the acetone will take off the hazy sealant but also some of the black dye, so test in an inconspicuous spot.