Os sepium "sepia bone, sepia shell or scallop", as "back bone" is a compression-stable inner buoyancy body of the ten-armed cuttlefish species Sepia. The main material of Schulps is aragonite, a calcium carbonate.

Microscopically, the Schulp consists of thin aragonite plates, which are supported against each other by numerous mini-columns. The formation of the fine limestone structures is made possible by the mineral components being attached to the chitin structures that give the limestone its shape. The calcification occurs in particular with increased CO2 partial pressure in seawater.

The Ossa Sepia casting technique has been known since ancient times and is still used today to create individual pieces of jewellery. Silver is poured into the sepia bowl. The wavy structure of the sepia shells is reflected in the piece of jewellery, so that each cast leaves its individual imprint. We have refined, reinterpreted and perfected this old technique.

The precise molding but also the new way of dealing with deformation and shaping led to an innovation in jewelry production. Hardly achievable by human hands, nature as the master has raised the play with dullness and gloss to a new level that has never been seen before. The result is exceptional jewelry, fine jewelry with a connection to the beauty of the sea and the diverse patterns of organic life.