Rochlitz porphyry tuff ("Rochlitzer Porphyrtuff"): A candidate for "global Heritage Stone Resource" designation from Germany

Abstract

Rochlitz porphyry tuff ("Rochlitzer Porphyrtuff"), a slightly welded ignimbrite from the North Saxon Volcanic Complex - a Permian supervolcano in East Germany - was used for millstones already in Neolithic age. The first use as building and sculpturing stone dates back to the early 12th century, when quarries at the Rochlitz Mountain ("Rochlitzer Berg") provided stone blocks for ashlars, sculptures and other purposes in the region between Leipzig and Chemnitz. In the first half of the 20th century, the material was used for buildings in many other German cities, like Berlin, Dresden, Frankfurt, Hamburg, and Munich. Moreover, it was applied in Kaliningrad (Russia), Vienna (Austria) as well as in some places in the Czech Republic, Poland and Denmark. The stone is presented with its petrographic and technical properties. Furthermore, the use in ancient and modern buildings, the quarrying techniques and heritage issues are discussed. The old quarry area of the Rochlitz Mountain is part of the German National Geopark "Porphyrland", and two quarries are still producing stone for construction and restoration purposes as well as for sculptures.