Besides silver veins, coloured gemstones were Saxony’s most valuable natural resource. As early as 1575 Elector Augustus (1553–1586) commissioned Giovanni Maria Nosseni to undertake a systematic search for new deposits. However, it was not until February 1697, under the elector of Saxony Frederick Augustus I (Augustus the Strong), that several varieties of agate were found in the village of Halsbach, near Freiburg, in the Saxon Erzgebirge. Polished samples displaying the quality and beauty of the stone were produced at a polishing mill outside Dresden. After 1708 Frederick Augustus I, who also ruled Poland-Lithuania as King Augustus II, engaged Johann Friedrich Böttger (1682–1719), the inventor of Meissen’s famous porcelain, to oversee a grinding and polishing mill for Saxon gemstones, which operated from 1713 to 1715. After Augsburg, Dresden became one of central Europe's most important centers for the production of fine hardstone creations.