The new flagstone kitchen counter keeps staining. We were assured that would not be the case when it was purchased. It has been sealed (don't know with what) but that doesn't seem to help. It has been buffed to remove the stains but not all of the staining comes out. What is the proper sealer and general care for flagstone used in a kitchen? The area includes work surfaces and
has been used extensively in the kitchen and elsewhere in the home and we don't want it to discolor and not match the rest. Thank you. Alicia6