Chemistry of Bean Jasper

Its main component is silicon dioxide (SiO₂), which occurs in microcrystalline form as quartz or chalcedony. This fine structure gives the stone its exceptional hardness and silky luster.

But it is the accompanying substances that make each piece of Bohnerzjasper a unique and distinctive specimen.
Iron oxides and hydroxides (Fe₂O₃, FeO(OH)) give it its characteristic red, brown and yellow tones.
Calcium carbonate (CaCO₃), phosphate (PO₄³⁻), hydroxide (OH⁻) and carbonate groups (CO₃²⁻) as well as traces of organic carbon (C) complete the complex structure and tell of the changing geochemical conditions of its formation.

A stone that speaks the language of geological time and at the same time preserves the history of craftsmanship in the Markgräflerland region.

Chemical composition (simplified):
SiO₂ (with traces of Fe, Ca, C, OH⁻, CO₃²⁻, PO₄³⁻)

My mission: To revive a forgotten tradition

Historical sources show that cities like Freiburg and Waldkirch were among the most important lapidary centers in Europe between 1400 and 1800. There, Bohnerzjasper was processed in large quantities into artistic ornaments and jewelry. Over time, however, this craft fell into oblivion.

With my workshop, I want to revive this tradition and restore the Markgräfler bog jasper to the appreciation it deserves. I continue the old craftsmanship and combine the rich history of this unique stone with contemporary design and modern forms.

What makes Bohnerzjasper so special?

Geology – Millions of years of Earth's history:
The bog jasper originated from prehistoric Jurassic cherts of the Lower Malm (Oxfordian). The iron oxide contained in the so-called red earth gives the jasper nodules their intense yellow and red tones, a striking interplay of colors that makes each stone unique.

Cultural history - From tool to jewelry:
Its history dates back to the Middle Stone Age (around 27,000 BC). For millennia, it served first as tool material and later became a sought-after raw material for European grinding mills.

A piece of jewelry with soul

When you wear a piece of jewelry made from Markgräfler Bohnerzjasper, you are not only wearing an extraordinary mineral, but a piece of cultural history that is up to 27,000 years old.