Calcium carbonate, or CaCO3, comprises more than 4% of the earth’s crust and is found throughout the world. Its most common natural forms are chalk, limestone, and marble, produced by the sedimentation of the shells of small fossilized snails, shellfish, and coral over millions of years. Although all three forms are identical in chemical terms, they differ in many other respects, including purity, whiteness, thickness and homogeneity. Calcium carbonate is one of the most useful and versatile materials known to man.
Often refereed to as Agricultural Lime. Crushed limestone is used to neutralize acids in the soil and so create the optimum soil conditions for crop growth. They also help to break down clays as described above, improving the soil structure, thus improving drainage and reducing soil erosion. Further, they provide a source of calcium ions that are an important plant nutrient.