Why is granite harder than sandstone?
Granite is a igneous rock which means it was once lava flowing out of a volcano. This rock has hardened and cooled over 1000s of years but still keeps the dense properties of magma. sandstone on the other hand is a sedimentary rock which means it was formed by sand which was pushed together with huge pressure. Naturally granite going to be harder as it is not formed from sand but from molten rock.
