Angular gravels for driveways are usually sourced from quarries, a by-product of the crushing processes, whereas rounded driveway gravels are from a fluvial source, such as an old river bed, beaches, and channel dredging. Driveway Gravels can be of almost any colour, depending on the parent rock type, or even a multi-coloured blend. Gravel driveways will give a nice touch to your home.