Marble is a metamorphic rock that forms when limestone is subjected to the heat and pressure of metamorphism. It is composed primarily of calcite, and usually contains other minerals such as clay minerals, micas, quartz, pyrite, iron oxides and graphite.
Marble occurs in large deposits that can be hundreds of feet thick and geographically extensive. Most marble is made into either crushed stone or dimension stone — produced by sawing marble into pieces of specific dimensions for monuments, buildings, sculptures, paving and other projects.
Marble Countertop — What To Know