A compound is a substance that contains two or more elements close elementA pure substance that is made from only one type ... rocks are formed by magma that has cooled slowly, deep underground ...

“Geologically-speaking, it’s quite hard to make granite without water and plate tectonics, which is why we really don’t see that type of rock on other planets,” said Professor Stephen ...

Granite hardens within the earth’s crust ... causing them to change into another type of rock. They are usually resistant to weathering and erosion and are therefore very hard-wearing.