Gemstones are exposed to many different elements when you wear them. Because of this, an organic build-up or “film” can occur on created gemstones such as moissanite. It is not harmful to the gemstone however it cannot be removed with over the counter jewelry cleaner or with a jewelry store cleaning. This film can be easily removed with a Sunshine Polishing Cloth. Another option that works well would be to use any silversmith polish that can be found in your local hardware or grocery store. Feel free to contact our Customer Service department with any specific questions related to cleaning moissanite.