Champagne Limestone is one of the most consistent limestone available in the World. Champagne limestone is available in fine grain as well as medium grain. Champagne limestone comes in large size tiles like 24×24, 36×36, and 48×48 as well as slabs in various thicknesses.
Per Wikipedia, Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral and mollusks. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO3).
About 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. Most cave systems are through limestone bedrock.