Chalk is a soft, white, porous sedimentary rock made primarily of calcium carbonate. It is formed from the accumulation of tiny marine organisms, such as plankton, over millions of years. Chalk is commonly used in classrooms for writing on blackboards, as well as in art for drawing and sketching. In addition to its educational uses, chalk has applications in various industries. It is used in the production of cement, as a filler in paints, and even in agriculture to improve soil quality. Its versatility makes chalk an important material in both everyday life and industrial processes.