Care and maintenance of stones
Natural stones are a porous material so they are subject to irreversible stains, however, it must be regularly cleaned and maintained. For a daily cleaning, just use a solution of warm and soap or neutral detergent with a soft tissue. In the most persistent stains, bleach diluted in water can be used and rubbed gently, rinsing and drying very well to prevent corrosion of the stone.
You should not use abrasive cleaning products as they are very aggressive and can damage and remove the shine from the stone.