“Roter Feuerstein” (“red flint”) or “Helgoland flint” is occasionally found at the shores of the small archipelago of Helgoland in the North Sea. Helgoland consist of the two small islands of Helgoland and Düne. Red flint is exclusively found at Düne. The red color is caused by iron oxides and hydroxides. In particular larger flint nodules with a red core and a black and white cortex are highly valued since prehistoric times. First indications of its use are from the late Paleolithic (Federmesser and Ahrensburg-complexes). Most examples of the red flint implements are from TRB times and the last artifacts from this flint source are known from the dagger period (http://www.aggsbach.de/2010/09/late-neolithic-flint-dagger/.)
The most famous Helgoland flint find is the red axe rough-out ofthe Eenerveld deposition, found in 1940. Besides a rough-out the deposition contained some nodules, a partially polished and one fully polished flint axe.
About 200 thin butted axes from the early Funnel Beaker Culture (TRB) are known from the Netherlands, Germany, Denmark and Eastern Europe along the Baltic Sea. Axes from Helgoland flint from the western TBR-group in the Drenthe region were most probably locally produced, which is supported by the presence of axe production flakes of Helgoland flint in Drenthe. It is suggested that Helgoland flint was exchanged in the form of nodules instead of finished axes. This forms a clear contrast with the “ordinary” northern rectangular axes, which would have been exchanged as finished tools. In Northern Germany however, axes, daggers and chisels made from Helgoland flint seem also to be exported as finished artifacts (For example at Nieblum / Föhr).
Helgoland during the Neolithic was an island at least 65 km away from the coast. Even today cruising to this island may be problematic due to difficult water and strong tides; therefore the seafaring capabilities of Neolithic men earns our full respect.
Flint from Heligoland − the exploitation of a unique source of raw-material on the North Sea coast (via academia.edu)