Limestone is a kind of sedimentary stone that is found almost all over the Mediterranean and Europe.

Sedimentary stone or rock is formed when over billions and billions of years the layers of sand and mud at the bottom of lakes and oceans turn into rock.

Other examples of sedimentary rock are Sandstone, Conglomerate, Gypsum, Breccia, and Shale.

Limestone has about 50% of calcium carbonate, but because it is formed in wet areas, it also contains algae, shells, faecal matter, and fossils of animals.

Completely pure limestone is white, but since it has a mixture of minerals and other sediments, it sometimes is found in a lighter misty milky colour.

However, the colour of the limestone can be as different as that of the rainbow, because its colour is determined by the amount of calcium carbonate it contains.

Limestone is mainly used as construction materials. It is also used as an additive to paints, to make them thick.

They are added to the shingles of roofs, and tar on tiles. Limestone is also used to make other rock like marble, which is of even greater value.

Interestingly, bits of limestone are added to the foods of chicken because it is a valuable nutrient for them.