The quarry, which received its SSSI notification in 1994, takes its name from the nearby De Lank river.

The quarry produces typical biotite granites and are of such quality that a slab now forms the base section of the reception desk at the Geological Society of London.

[2] Other notable structures built of De Lank granite are the fourth Eddystone Lighthouse, 1882; the Royal Opera House in Covent Garden, London and Portcullis House,the New Parliamentary Building in Whitehall, London [3] De Lank quarry is located on the edge of the igneous rocks that form the majority of Bodmin moor, with the change to slate formations occurring less than 0.5 miles (0.80 km) to the west.

[6] To achieve this one of the sidings at Wenfordbridge extended on a sharp curve across a road and then over several fields before going down a rope-worked incline to the quarry below.

Originally horses were used to haul wagons on this private line from Wenfordbridge, but between 1926 and 1950 it was worked by an 0-4-0 simplex locomotive.