For this church:
With the exception of a modern brick vestry to the north of the chancel, Keyworth church is built of stone with a tiled roof. Two kinds of stone predominate:
1Most of the nave, chancel and aisles are of local Blue Lias limestone, of which some is thinly laminated and flaky, while some is more robust in appearance, with massive blocks two feet long and over six inches thick. The precise source is unknown; there are no nearby quarries or pits in the Blue Lias still visible, and any replacements have to be brought from a quarry of similar stone in Somerset.
2The tower and south porch are made of Triassic sandstone, probably from a quarry near Castle Donington. It is more uniformly strong than the Blue Lias, and therefore more able to bear the greater weight of the tower. It has also been dressed to give the finished appearance of ashlar, appropriate to the most prominent part of the building. A distinctive feature of this stone is the patterning produced by compression as the sediment was being laid down, a process known as soft sediment deformation. A second kind of Triassic sandstone, a much softer and finer pale reddish stone, is found in some of the window moulding and tracery.
Other stone to be found includes:
3Magnesian limestone, a sandy limestone used in the mouldings around the windows and porch entrance, and also in the mullions and tracery of the windows. It was probably obtained from near Mansfield.
4Carboniferous sandstone in much of the repair work on the mouldings, undertaken in the 1870s (chancel and nave) and tower (1927/8). This is a hard material, relatively recently cut and distinguished by its smooth surfaces and sharp edges. It was probably obtained from near the Notts/Derbys border.
5Small quantities of Oolitic limestone (Middle Jurassic from Ancaster, Lincolnshire) and glacial erratics (from local boulder clay) to fill gaps left by the degrading of individual blocks in the church walls.
Two features of interest on the exterior south wall of the nave are a sundial in badly worn sandstone, and some deep grooves in the adjoining sandstone window ledge, said to be the result of its frequent use for sharpening arrows, spears, knives and swords.