The natural stones that are used around the world today, are grouped into four categories - Sedimentary, Metamorphic, Igneous and Man-made stone.

Limestone is categorized as Sedimentary stone. Sedimentary stone came from organic elements such as glaciers, rivers, wind, oceans, and plants. Tiny sedimentary pieces broke off form these elements and accumulated to from rock beds. They were bonded through millions of years of heat and pressure.

Limestone has a smooth granular surface and varies in hardness. Some dense limestone can be polished. Usually consistent in color with little or no veining and most common colors are black, grey, white, yellow or brown.