Silestone is a very hardy type of quartz countertop. It is nearly impossible to scratch and even harder to stain--even though it never has to be sealed. If you do develop a stain on your Silestone, it may either be a caked-on substance or a chemical mark such as those left by hard water. You will easily be able to remove these problem stains with common household items.
Clean the counter. This will help you distinguish between everyday grime and stains. Use the glass cleaner and a cleaning rag to bring your Silestone to a bright shine.
Scrape off any raised stains. Many stains are actually build-up that is a result of food or gum being left on the Silestone for too long. You will be able to feel the raised surface of the stain when you run your fingers over it. Use the razor to scrape off the gunk. It will not scrape the silestone.
Treat flat stains with vinegar, rubbing alcohol or nail polish. All of these cleaners will break down chemical stains and build-up without harming the Silestone. Start out with vinegar, which is the weakest option. Use a cleaning rag saturated with vinegar to clean the stain. Lay the rag over the stain for about 10 minutes, then wipe it clean. If the vinegar leaves traces of the stain behind, move on to rubbing alcohol, and then nail polish remover, using the same process.
Wipe down the counter again. Clean off the agents you used to remove the stains, using the glass cleaner. Be very thorough and use firm pressure.
Dry the Silestone. Use a clean, dry cloth to dry off the Silestone so that no traces of any cleaning agents remain.
Avoid oily cleaners and oven/grill cleaners, since they can dull your Silestone finish.