Like granite, the term "marble" has both a geological and commercial definition. Geologically, marble is a "metamorphic rock consisting of fine to coarse-grained recrystallized calcite and/or dolomite." Commercially, the term marble is used to describe any crystallized carbonate rock including true marble and certain limestones (orthomarble) that is capable of taking a polish. Travertine and serpentine, while not true marbles, are usually included in the commercial definition of marble.

 

A geologic Marble of pure calcite or dolomite would be white. Marbles are available in a vast array of colors, and the variety of colors is the result of impurities found in the marbles, such as iron oxides, carbonaceous minerals, mica, chlorite or silicate.

 

The Marble Institute of America defines 4 classes of marbles in descending order of soundness as A, B, C, & D. Research of a particular marble is necessary to determine its suitability for the kitchen application, particularly exterior applications. Marble for kitchen in the C & D soundness classifications have the most limitations in fabrication and application, yet many of the highly decorative marbles with exotic veining fall into these groups.

 

There is a wide variation of physical properties in the stones that make up the marble group. Generally, the flexural strength, compressive strength, and abrasion resistance are lower than what is typically found in the granite group. This may result in either reduced spans or increased thicknesses for cladding, or increased wear in high traffic areas. As long as the material is properly selected for the kitchen application, the performance should be satisfactory.

 

Some marbles exhibit hysteretic behavior after repeated heating and cooling cycles. This hysteresis is typically evident by a bowing of the marble panels, and can normally be eliminated if the panels are of sufficient thickness. Research of the particular marble should be done to determine its vulnerability to this phenomenon.