Stiffkey is first evidenced in the
Domesday Book of 1086, and means 'stump island, island with stumps of trees'. The local historical pronunciation of the village is 'Stiff-key' and not ‘Stew-key’. The mis-pronunciation is primarily due to the underlying
glauconitic clays (blue-green clays – formerly Blue Marl), BGS lexicon
lithological description: Pale to dark grey or blue-grey clay or mudstone, glauconitic in part, with a sandy base. Discrete bands of phosphatic nodules (commonly preserving fossils), some pyrite and calcareous nodules. In Norfolk, the
Cretaceous Gault Formation becomes
calcareous before passing northwards into the Hunstanton Formation ("Red Chalk"). In places thin, variable junction beds at the base include some
limestones. (BGS lexicon: Gault Formation which belongs to the Selbourne Group). The blue clays are known locally as 'Norfolk Stew', hence the name 'Stew-Key' [Stew-quay] as the flats there and the quays use the underlying blue clays (muds) weathered from Cretaceous bedrock. As already noted the local fauna of cockles can be stained with relation to their habitat. Glauconite is an iron- and potassium-rich mineral and the solid phase reactions can produce the iron- and potassium-rich dye
Prussian blue. The correct and locally used pronunciation is ‘Stiff-key’. In the Domesday book it is spelt ‘Stiucai’, when this was written there were no separate letters for ‘V’ and ‘U’. All names with a ‘V’ sound were spelt with a ‘U’. It is thought that ‘Stew-key’ arose from the mis-reading of the Domesday spelling. Later on English spelling evolved, and by 1300 the spelling ‘Styfkey’ appeared in documents, which is pretty hard to mis-represent. [Stiffkey with Cockthorpe: A story of Norfolk People, 2013]. ==Wildlife sites==