Cleaning is the set of treatments aimed at removing impurities, incrustations and deposits of various kinds from the surface of stone materials. Marbles, granites and natural stones are not all the same and therefore the treatments to be performed are also different:
For the application, soak and rub more or less vigorously a Scotch-Brite pad (strong abrasive sponge usually green) or, if necessary, a metal scourer, always doing a preventive test on a small and hidden portion of material. Always rinse thoroughly with water after each treatment and when using aggressive detergents, it is recommended to apply a neutral detergent that inhibits its action. In the case of a polished finish, a subsequent treatment with wax or polishing powder paste may be necessary to restore the original shine.
Never use detergent products that contain hydrofluoric acid (HF) or phosphoric acid ( H3PO4) on any natural stone, including granite, as they have the power to completely dissolve the quartz of silicates.
Generic commercial anti-scale products should be avoided as they are strong acids (they may also contain phosphoric or hydrofluoric acid) which, especially on marble, travertine, slate and onyx or materials consisting almost entirely of limestone, produce surface cavitations due to calcite dissolving.
Hydrochloric acid (HCL) can lead to alterations of the colour or swellings on the silicates, it is however used to recover very degraded granite floors but it is a treatment for rehabilitating the original colour through corrosion and removal of the surface part of the material evidently intended to be used by professional applicators.