White residue can ruin the look of your stone worktops. There are a number possible causes and, in order to resolve this problem, you first need to identify the cause. In addition, identifying the cause will also help you prevent such residue from building up in the future. Soap and cosmetics If you use a nylon pan scraper or a razor blade to try to gently scrape the residue off the surface, you will soon be able to tell if it is indeed soap, cleaning product or cosmetic residue. If scraping the surface removes the substance easily, you can then place it in the sink and mix it up with water. If you notice that it has an oily feel, then it is most likely lotion, conditioner or something similar. If it is soapy, then it is obviously a build up of soap or a cleaning product. Hard water If