Siegburgite
Siegburgite is a type of amber that was described by Arnold von Lasaulx in 1875 . The name goes back to the place where it was found in Siegburg near Bonn . In the tertiary sands of the Upper Oligocene ( Chattian ), solid, gray-white, kidney-shaped and irregularly shaped bulbous concretions were produced during sand mining in the Siegburg and Troisdorf area . They consist of quartz sand that is solidified by a binder made from fossil resin . It does not appear in any other form at the site. A more recent description of the circumstances of the find dates from 1968. Because of the easy flammability of the resin, the concretions were used as fuel and because of the aromatic smell when burned as sacred incense.
Obviously, the very thin resin of the producer plant had dripped onto the sand surface and had filled the pore volume of the sand, the resin content is usually less than 50%. Fossil resins in this form are very rare. Another "sand amber", which is not identical to Siegburgite, was only described from the lower Miocene of Lausitz .
The Siegburgite has a brown-red to hyacinth-red color, according to recent studies it is very brittle and easy to pulverize. Klinger & Pitschki found a lot of styrene in the pyrolysis distillate and also cinnamic acid , benzene and toluene . The succinic acid characteristic of amber (succinite) is absent. They concluded that only one species of the genus Liquidambar ( sweetgum trees , family: Hamamelidaceae, witch hazel family ) could be considered as a producer plant . Because of the high proportion of aromatic compounds, Siegburgite is a natural polystyrene . According to the Anderson & Grelling system , Siegburgite belongs to class III.
In the 1990s, a phase of confusion began due to the confusion between Siegburgite and the amber species Beckerite . The beckerite was described by Pieszczek in 1880 on the basis of finds from the Samland . For this light gray-brown resin with a matt surface in a bulbous and lamellar shape and with frequent wood marks, an extreme toughness was mentioned as a special feature, which made pulverization very difficult. The absence of succinic acid was also found. In the 1986 publication on the types of amber from the Bitterfeld amber deposit , one of the fossil resins was designated as beckerite, in particular because of its toughness and the external appearance of the finds. A considerable proportion of aromatic compounds was detected by the infrared spectrum, similar to that of Siegburgite. Infrared spectroscopic follow-up examinations of pieces called Beckerite from various scientific collections showed that this evidence does not contain any aromatic compounds and rather consists of heavily contaminated succinite. This led to the assumption that the Bitterfeld resin with aromatic components could be Siegburgite and not Beckerite. Attempts to provide direct evidence by comparing the infrared spectra of the Siegburg and Bitterfeld resins failed because of the high proportion of foreign components in the Siegburg material. Now that there are infrared spectra of the pure resin substance, it has been proven beyond doubt that the resin from Bitterfeld is not Siegburgite, and this is also proven by the deviating physical properties. So far, there has only been one secured site of Siegburgite.
Individual evidence
- ^ Arnold von Lasaulx: Mineralogisch-Krystallographische Notes, I: Siegburgit, a new fossil resin . In: New Yearbook for Mineralogy, Geology and Palaeontology , year 1875, Stuttgart 1875, pages 128-133 (online)
- ↑ Gerhard Hentschel: A fossil resin from the Tertiary of Siegburg . In: Der Aufschluss - Zeitschrift für die Freunde der Mineralogie und Geologie , Volume 19, Göttingen 1968, pages 289–290.
- ↑ Roland Fuhrmann: The sand amber from the Miocene of Lausitz, a Siegburgite? In: Mauritiana , Volume 24, Altenburg 2012, ISSN 0233-173X , pages 24-28 PDF
- ↑ a b Roland Fuhrmann: The bitterfield amber species. In: Mauritiana , Volume 21, Altenburg 2010, ISSN 0233-173X , pages 13-58, PDF
- ↑ H. Klinger, R. Pitschki: Above the siegburgite. In: Reports of the German Chemical Society in Berlin , Volume 17, Issue 2, Berlin 1884, pages 2742–2746; Refereed in: New Yearbook for Mineralogy, Geology and Palaeontology , year 1885, Stuttgart 1885, pages 377–378 (online)
- ↑ Ken B. Anderson, John C. Crelling: Amber, Resinite, and Fossil Resins . In: ACS Symposium . Series 617, Washington DC 1995, ISBN 978-0-8412-3336-2
- ↑ Ernst Pieszczek: About some new resin-like fossils of the East Prussian Samland . In: Archives for Pharmacy , 3rd series, Volume 14, Issue 6, Halle / Saale 1880, pages 433-436
- ^ Roland Fuhrmann, Rolf Borsdorf: The amber types of the Lower Miocene of Bitterfeld. In: Journal for Applied Geology , Volume 32, Berlin 1986, pages 309-316, PDF .
- ↑ Barbara Kosmowska-Ceranowicz, Günter Krumbiegel : Geology and history of Bitterfeld amber and other fossil resins . In: Hallesches Jahrbuch für Geoswissenschaften , Volume 14, Gotha 1989, pages 1-25
- ^ CW Beck, JB Lambert, JS Frye: Beckerite . In: Physics and Chemistry of Minerals , Volume 13, Heidelberg 1986, pages 411-414.
- ↑ Günter Krumbiegel, Barbara Kosmowska-Ceranowicz: occurrence of Glessit, siegburgite and Krantzit tertiary Central Germany (Bitterfeld, Niederlausitz) (?) . In: Fundgrube , Volume 26, Issue 3, Berlin 1990, pages 78-81.
- ↑ Günter Krumbiegel, Barbara Kosmowska-Ceranowicz: Fossil Resins around Halle (Saale) in the collection of the Museum of the Geisel Martin Luther University of Halle-Wittenberg . In: Scientific journal of the University of Halle , Volume XXXXI'92, Issue 6, Halle 1992, pages 5-35
literature
- Norbert Vávra: Chemistry of Baltic and Bitterfeld amber: methods, possibilities, results . In excursion guide and publications of the German Society for Geosciences (EDGG) , issue 236, pp. 69–76, 5 illustrations, 2008. ISBN 978-3-936617-86-3
