Marble is a metamorphic rock found in the mountainous regions of most countries of the world. The calcite crystal is the basic building block of true marbles. The calcite crystal is vulnerable to attack by mild acids, including those commonly found in kitchen and bar settings. The user selecting marble for these applications should be aware of, and accepting of the maintenance and patina that is to be anticipated with this combination. Acid rain and other weathering elements can also affect exterior marble installations, and exterior applications are generally limited to white marbles, with some exceptions.
Serpentine is a magnesium-silicate based stone that exhibits greater acid resistance and abrasion resistance than does a true marble. These properties make serpentine a common choice for both kitchen counter and exterior application.