Gravel, on the other hand, is like a melting pot of a lot of different rock pieces, including limestone, basalt, and sandstone. Put simply, limestone is a type of rock that is formed by organisms ...

Igneous rocks ... type of rock. They are usually resistant to weathering and erosion and are therefore very hard-wearing. Examples of metamorphic rocks include marble, which originates from ...

The only exception to the rule is Country Tyrone which has a bit of everything - clay, basalt, gabbro, granite, schist, limestone, and sandstone ... to form a new type of rock called sedimentary ...