Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite.
Geologists use the term "marble" to refer to metamorphosed limestone; however stonemasons use the term more broadly to encompass unmetamorphosed limestone.
Marble is commonly used for sculpture and as a building material.
Pebbles come in various colors and textures, and can have streaks of quartz and different colored sedimentary rock. Pebbles are mostly smooth but, dependent on how frequently they come in contact with the sea, they can have marks of contact with other rocks or pebbles. Pebbles left above the high water mark may have growths of organisms such as lichen on them, signifying the lack of contact with sea water.