Limestone is a sedimentary rock which is made of calcite and aragonite (both forms of calcium carbonate). It makes up approximately 10% of all of the Earth’s sedimentary rocks. Although it is widely believed to be white in color, it can actually have many different colors because of impurities in the rock. It has been used for centuries for a wide variety of applications.
Uses of limestone
- Limestone is commonly used for building. It is easy to obtain, can be cut into blocks and is long lasting. Many buildings from the late 19th and early 20th century are made of limestone. The Great Pyramid is built entirely from limestone.
- It is also used for sculptures, statues and monuments because it is easy to carve. Unfortunately, limestone reacts to acid and many statues and buildings are being destroyed by acid rain.
- It is a common ingredient of cement, concrete and mortar.
- The chippings of limestone are often mixed with tarmac for roads and paths.
- Ground limestone is often used to neutralize acidic soil and water.
- Limestone is used in certain types of glassmaking to purify the glass during its molten stage.
- It is used as white pigment in many products such as toothpaste, paint, plastic etc.
- A purified form of limestone can be added to fortify breakfast cereal with calcium. It is also added to livestock feed as a source of calcium.
- It is used to extract iron from iron ore in a blast furnace.