* Wash it using warm water and detergent and dry it with a soft cloth several times a week. Never use soap or any abrasive element. Food stains can be lifted by hydrogen peroxide, and ink can be removed with water and bleach. * These marbles are delicate, and they need to be sealed 2-4 times a year. * Polishing will help to make it look shiny and leave a water-resistant to prevent etching or spills. * To fix any crack or etch, hire professionals.