Glosssary of Stone & Marble Industry Terms

Acidity and Alkalinity
Opposite terms designating a reactive condition at which substances exist. Acidity in its simplest definition is the term applied to a solution with a pH of less than 7. The lower the pH, the stronger the acidity and the higher the pH, the stronger the alkalinity. A neutral pH (i.e. neither acidic or alkaline) is, strictly speaking, 7; but the neutral zone, with regard to stone, is approximately 6 to 8. Another term for alkalinity is basic and substances which are basic are called bases. Acids and bases are reactive to each other. Marble and calcite stones are basic substances and therefore react with acids. Hence, acidic substances such as vinegar and carbonated beverages can cause Etching of marble. Granite and siliceous stones are not basic and, in fact, are chemically much less vulnerable to damage from either acidity or alkalinity.

Abrasions
A marring of the surface of marble caused by physical trauma. The marring is generally very slight and homogeneous such that there is no distinguishable border and has no perceptible depth.

Buffing
Using a non-abrasive pad attached to a machine which rotates the pad in a circular fashion over the stone, generally between 150-300 RPM. Polishing formulations containing micro-fine abrasive materials are used with buffing to produce a more reflective gloss on the surface of stone. Waxes are also used with buffing to enhance the gloss of polished stone.

Coating
Any material that clings uniformly to the outer surface of the stone. Under some circumstances acrylic, plastic, or wax materials are used as surface protectants or for cosmetic enhancement

Cleaning
The process by which dirt, oils, or foreign materials are removed from the surface of natural stone.

Dullness
A decrease in the reflective quality of the stone polish.

Etching
A chemically induced marring (marking) of the polished stone surface creating dullness. Depending on the severity, etching may create a tangible roughness on the stone surface. Etching is generally caused by acids; this typically occurs when food or acidic drinks contact marble or Limestone.

Grit
A measure of the particle size of abrasive material. The higher the grit, the smaller the particle size and the smoother the resulting surface.

Honing
To grind a surface with a high grit material to a uniform specification without producing a reflective surface.

Maintenance
The process of providing protection and cleaning.

pH
A symbol for the degree of acidity or alkalinity of a solution. A mathematical expression relating to the hydrogen ion concentration of a solution. (see Acidity and Alkalinity)

Polishing
To smooth or brighten a surface increasing the reflective quality and luster by chemical or physical processes.

Refinishing
To return a high gloss polish to a stone which is dulled and marred.

Restoration
The chemical and physical processes required to renew the smoothness and polish of marble that has been etched or scratched.

Scratches
The marring of the surface caused by physical trauma such as small stones or sand embedded in shoes scraping across a marble floor.

Staining
The absorption of foreign pigments or oils into the porous stone causing discoloration.

Sealing
The application of a material which penetrates the stone and provides water and oil repellency to prevent the absorption of oils and pigments into stone thereby retarding stains.

Stripping
The removal of coatings, such as waxes, acrylics, and heavy soiling from the surface of stone.