Red and green stones, angular and interspersed with calcite veins - the radiolarites bring color to the gray gravel banks!
To get to the place of origin of these rocks, one would have to use a diving robot nowadays. In the deep sea areas (3,500 - 5,000 m) of the Urpazifiks it developed 150 million years ago from Radiolarienskeletten.

Radiolarians are single-celled organisms. Their inner skeleton consists of silica crystals, which, unlike calcium compounds, do not dissolve even at this ocean depth.

The radiolarite is a hard rock. In the Stone Age, it was used to make tools such as arrowheads.