| Reference | F3 |
| NAME | Dukes |
| TYPE | Sandstone |
| GEOLOGY | Upper Carboniferous. Millstone Grit |
| COUNTY | Derbyshire |
| COLOUR | Pink/lilac, often with pronounced reddened bands |
| TEXTURE | Medium grained grit with some coarser material |
| BLOCK SIZE LXBXH (mm) | 1400x900x700mm |
| SUITABILITY | Ashlar, weathering courses and dressings |
| USES (1) | Mappa Mundi Chained Library, Hereford |
| USES (2) | Trent Bridge, Nottingham |
| USES (3) | Railway Stations between Derby and Crewe |
| USES (4) | Hereford Cathedral |
| Stone Names | Ashover Grit |