Stains are a natural byproduct of cooking on stones, especially if you spill something on the stone. With normal use and care, your stone will take on some mild, light coloring due to the food being cooked directly on it. More significant stains are typically the result of something being spilled on the stone, such as oils, sauce, or other ingredients.
Stains will not impact the effectiveness of the stone.
For general cleaning instructions, click here.