Idar and Oberstein are twin towns on the River Nahe that were united in a single administration, together with some adjacent communities, in 1933. Agate, jasper, amethyst and other gemstone have been mined for centuries in the hills that line the Nahe, and the towns developed into the principal jewellery manufacturing area in Germany.
The German Gemstone Museum displays several thousand varieties of stone, and shows the ways in which they have been worked in the past.
One of Idar-Oberstein’s most celebrated manufacturers was Jakob Bengel, who set up a company to manufacture chains for pocket watches in 1873. From about 1923 he began to use galalith, a casein-based, horn-like plastic, which he most commonly combined with silver-grey chromium to make jewellery in the Art Deco and Bauhaus styles. His factory was taken over for war production in 1939 and his work was subsequently neglected, but it was realised that pattern books, tools and stocks of unsold pieces remained in some of the factory buildings, in the villa in which he once lived and in the houses that he built for his workpeople. A trust was set up in 2001 to preserve and present the whole complex as an industrial monument where visitors are able to see examples of Bengel’s work, and displays illustrating the industrialisation of the jewellery industry, as well as to meet artists in residence.
The wider aspects of the industry can be experienced by following the two trails, with a total length of 48 km, set up by the German Gemstone Route, which link together all the sites of interest around Idar-Oberstein, including a mine at Steinkaulenberg, an agate mill at Weiherschleife and a gemstone garden at Kempfeld.