Thanks all! @joseph_corlett Thank you for letting me know! I have someone coming out tomorrow to take a look. When I bought the place, they had let me know the countertops and bathroom was quartz so now will definitely ask the pro that comes on Monday what they think it is. If it is not quartz, hopefully the old owners did not purposely misrepresent!
@ci_lantro We think it is what the cleaners used because we have had shampoo bottles on the ledge for years and never had an issue. After the cleaners came, we picked up the bottles and the damage was directly under the bottles so we think the cleaning stuff was accidentally not rinsed and must have been trapped under.
Q