The mine was opened, as "Gyfeillon Pit", in August 1851 by John Calvert, an engineer from Yorkshire, who had already sunk the Newbridge Colliery (later to become part of the Maritime Collieries, near Graig, Pontypridd).
The colliery initially had three shafts: Hetty Pit (downcast, later upcast), Pit No. 2 and Pit No. 3 (downcast).