Abstract: A process for cleaning and conditioning marble and similar substances whereby a first mixture formed from zinc sulfate solution, an abrasive, and a thickener is used to mechanically and chemically clean and prepare for the reception of a second aqueous solution formed of fluosilicates of the group consisting of the alkaline earth metals and zinc, and a monocarboxylic aliphatic organic acid, such as acetic. The first mixture is applied with buffing means, completely flushed with water, and removed. The second solution is applied and partially removed with buffing means. As a result of these steps, the surface of the treated substance is given a brilliant glass-like finish.