Museum für Naturkunde
Chemnitz

Our Petrographic Collection

Collection of vulcanic rocks
The collection of vulcanic rocks of Alfons Stübel (1835-1904) derives from European vulcanic regions. The rhyolite or porphyry balls also called "fossilised nuts", play an important role within the collection. During the first third of the 20th century the deposition of rhyolite balls in the surroundings of Chemnitz also inspired Ernst Stecher (1861-1935), who intensively researched on their formation. His "theory of bombs" was accepeted over decades. Thus, he interpreted these balls as bombs of vulcanic eruptions. Even pupils from Chemnitz got fascinated by theories of the formation of equatorial bulge by rotation. People collected masses of rhyolite balls in the the districts of Chemnitz (Furth, Altendorf and Gablenz) as well as near Hohenstein-Ernstthal and St. Egidien, mostly because of their agate filling.

Local collection of geological formations of Saxony
The local collection of geological formations of Saxony is divided in four domains: vulcanic and sedimentary rocks of Chemnitz, granulite mountain and Erzgebirge.

Collection of ashlar and decorative stones
291 million years ago numerous active volcanoes existed in europe from Scandinavia to the Mediterranean area. Also in Saxony witnesses of Permian volcanism can be found. The Beutenberg, the volcano of the Zeisigwald located northeast of Chemnitz, erupted in the Permian. Thanks to a multi-phase eruption, which led to the genesis of the "petrified forest", masses of volcanic ashes deposit on the area of the Zeisigwald and even fillled up the caldera of the former volcanic cone. The main sedimentary depositions of the volcanic eruption are lapilli and tuff, which ejected off the burning hot ash flows. All together it formed the unique tuff of the Zeisigwald, an appealing building material, which is applied for ashlar and decorative stones from the early Middle Ages.

Special collection of petroleum geology
Within this collection are peat, brown coal and black coal of different degree of coalification and fossil oil from German depositions.