Coal is a combustible black or brown sedimentary rock that is formed from the remains of plants that lived in swamps and marshes millions of years ago. These plants died and were buried under layers of mud and sand, and over time the heat and pressure caused them to turn into coal.
Limestone is a sedimentary rock that is formed from the accumulation of calcium carbonate, which is a compound that is found in the shells of marine organisms such as coral, clams, and snails. As these organisms die, their shells sink to the bottom of the ocean and accumulate, eventually forming limestone.
Here is a table summarizing the key differences between coal and limestone:
| Characteristic | Coal | Limestone |
|---|---|---|
| Composition | Organic matter from plants | Calcium carbonate (CaCO3) |
| Color | Black or brown | White or gray |
| Formation | Formed from the remains of plants that lived in swamps and marshes | Formed from the accumulation of calcium carbonate in the shells of marine organisms |
| Uses | Used as a fuel to generate electricity and heat | Used as a building material (e.g. for tiles and bricks, cement, fertilizer, road surfacing, paint, etc.)|
