Duxit

Duxit is a mostly black brown fossil resin from Miocenes lignite layers in the northern Bohemia. The resin is first mentioned in 1874 by Christian Dölter.^[1] It is named after the small Czech town Duchcov (German: Dux) in northern Bohemia, where it was found in the lignite mining Emeran. Not far from Duchcov Duxit is found since the 1980s in a lignite workhouse at Bílina. In the lower section of the mined here lignite occur grade category tree residues with Duxit. Mostly it involves Taxodium.

Properties

Doelter reported the following composition for the samples which were extracted in 1874 (air-dry basis): 78.25% carbon, 8.14% hydrogen, 13.19% oxygen and 0.42% sulfur. The specific gravity was determined 1.133. The sample was in alcohol sparingly soluble in benzene.^[1] Doelter noted a certain similarity of the analyzed sample resin to Walchowit, gave the resin but because of the opposite Walchowit significantly higher oxygen content and because of some differing physical properties has its own name. He has classified Duxit in the category of Retinite fossil resins. Already in the middle of the 20th century, Duxit was known as the "Resinous bitumen".^[2] Modern methods of investigation, such as the infrared spectroscopy shows that duxit is not a pure resin, but a mixture of saturated hydrocarbons and plant resins and waxes.^[3]

References

1. C. Doelter: Harz aus der Braunkohle von Dux. – In: Verh. Geol. Reichsanstalt, 17. März 1874: P. 145-146, Wien 1874.
2. J. Paclt: A System of Caustolites.– In: Tschermaks Mineral. Petr. Mitt. Bd. 3 (4): S. 332 – 347, Wien 1953.
3. N. Vávra et al.: Duxite and ist geochemical biomarkers („Chemofossils“) from Bilina open-cast mine in the North Bohemian Basin (Miocene, Chech Republic). – In: N. Jb. Geol. Paläont. (Mh.) 1997 (4): S. 223 -243, Stuttgart 1997.