Marble, like Limestone, Travertine, is calcite containing natural stone which make it very soft and sensitive. Marble is easily damaged by acids, abrasive and corrosive products or perhaps a product that is not designed for use on natural stone.

What is acid etching?

When an acidic product comes in contact with the surface of the marble the acid dissolves the calcite within the marble causing a dull area. This is called acid etching. This dull patch or acid etch is damage to the composition of the stone surface. Acid etching is not a stain but damage to the composition of the stone surface. 

Acid etching leaved dull marks

Acid-soluble stone materials such as the calcite in marble, limestone and travertine, as well as the internal cement that binds the resistant grains in sandstone, react with acidic solutions on contact, or on absorbing acid-forming gases in polluted air, such as oxides of sulfur or nitrogen. Acid erodes the stone, leaving dull marks on polished surfaces. In time it may cause deep pitting, eventually totally obliterating the forms of statues, memorials and other sculptures. Even mild household acids, including cola, wine, vinegar, lemon juice and milk, can damage vulnerable types of stone. The milder the acid, the longer it takes to etch calcite-based stone; stronger acids can cause dramatic damage in seconds.

Acid etching even whitened dark Marble

Acid etching is different from a stain as a stain can be cleaned out of the marble with the use of a the correct cleaning product. It must be mechanically re-polished or re-honed to regain the original polished or honed finish.

What need to do to prevent acid etching?

Marble must be sealed before use. It is more important to do daily care and cleaning. Wipe and clean immediately when the stains appear. Use right cleaning products for Marble. Consult professional company when there is something wrong to have the best result.

The difference of sealed and unsealed Marble