The hardstone workshops in Prague were the first true offshoots of the Galleria dei Lavori in Florence. Holy Roman Emperor Rudolf II of Habsburg (1552–1612) was described by contemporaries as "the greatest art patron in the world," and at his magnificent court princely art patronage in post-Renaissance Europe was elevated to unknown heights of humanistic refinement and excessive lavishness. By about 1600, "Rudolphine Prague" had developed into Europe's third major center of hardstone refinement, after Florence and Milan. The obsession with treasury objects, including pietre dure, was about to conquer all of Europe. The value of hardstone vessels made of rock crystal or jasper far surpassed that of paintings or sculpture as embodiments of princely wealth. Celebrated bronze sculptures, such as Leone Leoni's bust of Emperor Charles V and Adrian de Vries's bust of Rudolph II, were valued at a few hundred guilders shortly after the emperor's death, whereas one single basin made of "yellow jasper" was appraised at four thousand. Because of its richness in deposits of semiprecious stones, "Bohemia became known as a land where the stones which the cowherd threw at his flock were worth much more than a single animal," as Bohuslav Balbín noted in 1679. By attracting the hardstone craftsmen of the Miseroni family from Milan and the Castruccis from Florence, Rudolph achieved a major goal: uniting a group of superior artisans who would create only the best for his Kunstkammer. The Castruccis were the first to incorporate the pure shades of a single piece of stone into mosaic inventions, thus creating the first landscapes with accurate perspective in pietre dure panels.
Stuttgart and Freiburg-im-Breisgau
Two craftsmen stood out among the stoneworkers in Stuttgart. Hans Kobenhaupt worked there for the Kunstkammer of the ducal court of the Württemberg dynasty. The workshop applied mostly German hardstones, such as jasper and agate, from deposits around Idar and Oberstein in the Palatine. It has been suggested that the creator of the mounts for Kobenhaupt's vessels was the goldsmith François Guichard, who began working at the court in Stuttgart in 1610, shortly after Kobenhaupt arrived. It seems perfectly conceivable that several pieces represent collaborations. The rock-crystal and agate cutters in Freiburg could not compete with the virtuosity of their counterparts in Milan, but they developed their own style, mainly by refining small stone units that were assembled with precious metal, thus archiving an array of impressive objects for the southern German market. As late as 1753 there were at least fourteen hundred workers directly or indirectly connected to Freiburg's lapidary industry.
Hardstone cutting had already enjoyed a long tradition in this region, albeit under modest circumstances. This situation changed dramatically with the arrival of the sculptor Christoph Labhardt, a gifted artisan at the court of Landgrave Karl I of Hessen-Kassel (1654–1730). The discovery of deposits of agate, jasper, and other semiprecious stones in the Hessen region encouraged the Landgrave to invest in a stonecutting mill, which was erected about 1680. A record of 1697 mentions the production of "cups of crystal de Montagne [rock-crystal] with carved figures, scenes, and portraits, which were not seen before" made by the "famous Labhardt."
Besides silver veins, colored gemstones were Saxony’s most valuable natural resource. As early as 1575 Elector Augustus (r. 1553–86) 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 (ore mountains). Only polished samples displaying the Güthe und Schönheit (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. At the same time the ingenious Johann Melchior Dinglinger (1664–1731) created masterpieces that today are part of the German national heritage at the Grünes Gewolbe and not allowed to travel, and the gifted stonecutter Johann Christoph Hübner (1665–1739) collaborated with the sculptor Paul Heerrmann modeling busts of exceptional quality. Pietre dure reached a highpoint in Saxony with the work of Johann Christian Neuber (1736–1808), whose hardstone mosaic inventions mesmerized affluent society all over Europe in the last quarter of the eighteenth century.
Always concerned with the state of his country’s Exchequer, King Frederick the Great of Prussia (r. 1740–86) attempted to develop a luxury-goods industry on par with the one in France. The king ordered protectionist measures: "For the good of the Berlin gold workers . . . [we] totally forbade the import of all French gold boxes, étuis, and objets de bijou." The king's chamberlain, Michael Gabriel Fredersdorff, visited Paris in 1751 with the order to bring back a snuffbox, "the best that can be found there, so that we can find out how they are made." Frederick's mercantilist efforts eventually led to the establishment of successful manufactories of gold objects and jewelry in Berlin, and, after Augsburg and Dresden, Berlin became one of central Europe's most important centers for such artistic hardstone creations. The king also collected earlier Italian pietre dure works that he displayed in his painting gallery and his bedroom at his palace Sanssouci in Potsdam.