One of the most well-known Jaspers in Germany are the so-called „Bohnerzjaspisse “from the Markgräflerland. This Jaspers originally developed as flint concretions in jurassic limestones (Rauracium), which were enriched by procedures of the decomposition of the limestones. Iron-bearing “Bohnerze”resulted at the same time from the decomposition of the limestones. This wheathering caused the colour-changing of the jaspers(flints) too.
These jaspers were used for a long time in gemstone-cutterry. They show up e.g. in a table worked in the technic of “pietra dura” (ital. “hard stone”) standing in the hermitage in Saint Petersburg.
In the Jaspers sometimes occur fossils of brachiopodae or remnants of Crinoidae (sea-lilies). Sometimes the fossils arise in yellow color on red reason and are well recognizable in the red matrix. There are similarly formed and temporally oriented flints in the neighbouring Isteiner block. Unfortunately these do not show shine-red and yellow tones only shades in the grey-brown range.