Etchings Removal by Polishing
Etching is the white spots you find on marble surfaces, which are hard to get rid of, and are very unpleasant. Such spots may caused by acidic or alkaline liquids left on your surfaces. Marble typically composed of calcium carbonate fossils and can be easier etched than granite.
Etching may change the texture of marble surface to dull, non-uniform appearance. In some cases marble body can be etched, burned and melted to rough surface and destroyed to sand-like particles.
Some liquids will just etch your marble while other will etch and stain by penetrating.
In case your marble was stained and etched, for restoration you will need perform two different procedures, known as refinishing and poulticing.
Discoloration is a white spots that may cause on the dark marble. It is produced by mineral salt or calcium carried by water from concrete, thinset or other adhesives below the marble surface. Such minerals are sucking through the marble body, and then after drying leave spots and white crystal powder.