IDAR-OBERSTEIN

city, Rhineland-Palatinate Land (state), southwestern Germany, on the Nahe River at the mouth of the Idarbach. The present city was formed in 1933 through the union of Idar, Oberstein (both chartered in 1865), Algenrodt, and Tiefenstein. Until 1670 Idar and Oberstein belonged to the barons of Oberstein, later counts of Falkenstein; two ruined castles, the Alte Burg (c. 1197) and the Neues Schloss (c. 1330), date from that period. The towns changed hands several times before passing finally to the Birkenstein principality of Oldenburg in 1817. Idar-Oberstein has been important for precious-stone polishing, jewelry manufacture, and precious-metal working since the 17th century. There is a notable museum of gems in the city. Pop. (1989 est.) 33,227.