At www.q-mag.org/blood-red-flint-tools-souvenirs-of-doggerland.html … the North Sea island of Heligoland, a remnant of Doggerland, has something that is claimed to exist nowhere else, red silex (flint). It is the colour of blood and was used, it is further claimed, to imitate copper axes and tools, a sort of poor man's version of the latest fashion gizmo (when copper was a new and rare introduction into western Europe).
It pops up mostly on the continent, in nearby Poland and adjacent countries, and was a prized object of trade. We have plentiful supplies of brown and orange flint in the UK and I've seen examples of lovely axe heads made out of brown flint, but it never occurred to me it might be imitating a metal such as copper (which is not brown but red). The connection is therefore one of those geewhizz moments, a realisation that is obvious once it is made. The Heligoland flint is described as blood red – and is unique. We have examples of red pebbles and stones in the UK, popping up in surprising places (including chalk and flint geology). Heligoland was presumably all part of the chalk ridge that once extended from East Anglia across the North Sea. You can still see chalk rock on some beaches (near Cromer for example) and massive flint nodules (but of normal colouration) and clearly the chalk extended well offshore even in fairly recent times.
Doggerland is essentially the southern North Sea basin which was inundated around 6000BC. Heligoland must have been a high prominence on Doggerland and may have held some significance to later people – after the submergence. It was still being exploited for flint in the Late Neolithic period (of the third millennium BC). Good quality flint was used to make axes (or are they symbolic lightning bolts or meteorites), spear tips, knives and daggers, even sickle blades (to cut back brush and nettles as well as harvesting cereal crops). Sickles may also have been used in ceremonies – and a red sickly would have been a prized object in that situation. Arrow points, and larger points (for whatever purpose) were also made of flint as well as tools of various kinds. Only good quality flint, little weathered and freshly brought out of the chalk was suitable for the best of implements – and old flints left lying around were not favoured by craftsmen (if they had an option). Heligoland had flint mines. These are sometimes just a cavity or quarry like opening in a chalk hillside but at other times miners tunnelled deep into the chalk rock to obtain suitable noduless or laminate.