Grease stains and routine cleaning: 
Silestone recommends the use of SQT Natural Stone Detergent to maintain our worktops.
For grease stains, apply a small amount of SQT Natural Stone Detergent on the stain and rub with a non-metallic pan scourer (such as Scotch-Brite) until the stain disappears. Rinse immediately with clean water.

Hard water marks (glass and cup rings, etc): 
Sprinkle a solution of Cement cleaner and Terrazzo over the surface of the worktop and leave it to work for 1 minute. Rinse with clean water. Follow the manufacturer?s instructions and recommended uses of Cement cleaner and Terrazzo solutions. Do not apply to other products (taps, sink, etc.) as the product could damage their finish.

Silicone stains: 
Use a blade and a small amount of solvent (which does not contain dichloromethane, dichloromethylene, dichloramine). Rinse with clean water.

Hard to remove stains: 
For hard to remove stains sprinkle SQT Natural Stone Detergent over the affected area of Silestone, leave for 2 minutes and then rub vigorously with a non-metallic pan scourer (such as Scotch-Brite). Then rinse with plenty of clean water.

Loss of sheen: 
Loss of sheen on a Silestone worktop could be caused by the use of products (waxes, sprays, sealants, etc) designed to bring out its sheen, although these products lose their effect over time.This lack of sheen has nothing to do with the original, mechanical sheen the product had when it left the factory. 
To recover this natural sheen you can use a SQT Polishing Liquid for Marble, Granite and Quartz (new product)