"Mancetter Quarry is a source of Diorite which is a very hard granite like rock, often described as ‘salt and pepper’ because of its black and white colouring. The high skid resistance and durability of Diorite make it ideal for use in road building and maintenance.

Mancetter quarry is now worked by Tarmac who remove and process the Diorite rock. Crushed rocks, along with sands and gravels, are collectively known as aggregates. Because the high quality granite-like stone Diorite quarried at Mancetter is ideal for racetracks. This, together with the fact that the brother of one of the quarry shareholders ran Silverstone racetrack, meant that speed trials were held here."