Marble has very high porosity, making marble more susceptible to staining and discoloration. Marble is also more susceptible to staining and discoloration when exposed to water. Marble restoration services may be needed to protect marble surfaces from staining and discoloration. Marble is fragile and porous.  It will not survive a tough cleaning job without taking significant damage. And polishing marble is hard work. It requires a lot of skill and experience.