https://www.marblexinc.com/a-guide-to-the-care-and-cleaning-of-natural-stone/
oil-based stains (grease, tar, cooking oil, cosmetics) —will darken the stone and normally must be chemically dissolved so the stain's source can be rinsed away. clean gently with a soft liquid cleanser, household detergent, ammonia, mineral spirits, or acetone. biological stains (algae, mildew, lichens, moss...