Limestone - Uses of

Limestone is an abundant rock that can be used for a number of purposes. It was formed millions of years ago on the bed of relatively shallow tropical seas. It consists mainly of the mineral calcium carbonate which comes from two sources - shells and precipitation from seawater. There are many types of limestone, some hard, some soft. Rain is naturally slightly acidic because it contains dissolved carbon dioxide which forms a weak acid with water. Carbonates are one of the substances that react with both strong and weak acids, so slowly, over millions of years, rain will dissolve limestone to form some fascinating natural features like limestone sidewalks, caves, stalactites and stalagmites. This corrosion is accelerated by human influence since burning fossil fuels introduces sulfur and nitrogen oxides into the air which makes rain even more acidic.

There are large deposits of limestone in the UK which are quarried to provide us with this valuable resource. Many places where limestone appears at the surface of the Earth are areas of great natural beauty, for example the Peak District of Derbyshire. Quarrying raises many issues for local communities and the environment, for example, the destruction of natural habitats and local beauty spots whilst at the same time providing work for local people.

The building industry is a large consumer of limestone and its products, but there are so many more places where it is used. You are not expected to know all of them but it does help if you are aware of some e.g. cosmetics, food manufacturing and agriculture. The high school syllabus only asks that you know about the uses of limestone related to the building industry, so that means knowing that it is used directly as building stones and road foundations, and indirectly for making cement, mortar, glass and concrete. For high school, you will be required to consider and evaluate the environmental, social and economic effects of quarrying and using limestone for building. To do this, you need to be able to compare the benefits of using limestone against the negative aspects of quarrying. In the end though, it all comes down to the fact that without limestone, life would be very different so people on both sides of the argument need to make compromises. You also should be able to evaluate the advantages and disadvantages of using limestone, cement and concrete when compared to other building materials. You don't need to learn the properties of a load of other materials, the data you need will be given to you in the exam.