Duxite

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Duxite is a mostly black-brown fossil resin from Miocene lignite layers in northern Bohemia .

Occurrence

The Harz Mountains are first mentioned in writing in 1874. It is named after the small Czech town of Duchcow (German: Dux) in northern Bohemia, where it was found in the Emeran lignite mining.

Not far from Duchcow, Duxit has been found in an open-cast brown coal mine near Bílina since the 1980s . In the lower section of the lignite mined here, charred tree remains with duxite appear. Most of them are bald cypresses ( Taxodium ).

properties

The sample investigated on behalf of C. Doelter in 1874 gave the following composition (air-dry substance): 78.25% carbon, 8.14% hydrogen, 13.19% oxygen and 0.42% sulfur. The specific weight was found to be 1.133. The sample was hardly soluble in alcohol, but in benzene "... quite easily; also in carbon disulfide ”. Doelter found a certain similarity between the analyzed resin sample and walchowite , but gave the resin its own name because of the significantly higher oxygen content compared to walchowite and because of some different physical properties. Its classification of the material as a fossil resin belonging to the retinites was later confirmed in various analyzes. As early as the middle of the 20th century, however, the proposal came up to add Duxit to the "resinous bitumen " group. Modern examination methods, such as B. the infrared spectroscopy , with which material from the open-cast lignite mine near Bílina was analyzed, support this classification. Accordingly, Duxit is not a pure resin, but a mixture of saturated hydrocarbons as well as vegetable resins and waxes . According to Vávra, it is not an amber-like material. Some authors continue to place duxite among the accessory fossil resins.

Due to its physical and chemical properties, Duxit is not suitable for jewelry production.

literature

  • Günter Krumbiegel : Duxit - fossil resin and wax. In: Fossils , Volume 19, Issue 3, Korb 2002.
  • Norbert Vávra: The Chemistry of Amber - Facts, Findings and Opinions. In: Ann. Naturhist. Mus. 111 A: pp. 445–474, Vienna 2009.

Web links

Individual evidence

  1. ↑ a b C. Doelter: Resin from the lignite of Dux. - In: Verh. Geol. Reichsanstalt , 24 (meeting of March 17, 1874): pp. 145–146, Vienna 1874.
  2. ↑ J. Paclt: A System of Caustolites. - In: Tschermaks Mineral. Petr. Mitt. Vol. 3 (4): pp. 332–347, Vienna 1953.
  3. ^ N. Vávra et al .: Duxite and is geochemical biomarkers (“Chemofossils”) from Bilina open-cast mine in the North Bohemian Basin (Miocene, Chech Republic). - In: N. Jb.Geol.Paleont. (Mh.) 1997 (4): pp. 223-243, Stuttgart 1997.