Almost anything can be stained, but sealed granite will resist most common stains. Oil will penetrate this seal and can be difficult to remove. Oil spills should be cleaned up immediately. If oil has penetrated the seal, clean up as much of it as you can, then sprinkle baby powder or baking soda over the stain, cover with plastic wrap and allow it to sit for 24 hours. This will encourage the oil to be absorbed by the powder. Depending on how long the oil was allowed to sit on the top, this may require more than one application. In the case of stubborn stains you may want to call in a professional stone restorer.