Vitrain

The surface of a vitrain fragment isolated from low-carbon coal viewed under a microscope (x2000 magnification)

Vitrain is a lithotype of coal formed from the bark of large plants. Known for its glossy appearance, vitrain typically occurs in thin bands, between 3 and 10 millimeters in width. ^{[1] [2]} It has a brittle texture and typically forms cubical pieces when broken. ^[3] Chemically, vitrain stands out among coal lithotypes by hosting large concentrations of germanium. ^[4] Combustion of vitrain proves a vital source of germanium production, where the element can be extracted from the leftover ash.

References

1. "Vitrain | Railway, Transportation, Logistics | Britannica". www.britannica.com. Retrieved 2023-08-12.
2. Ward, Colin R. (2003). "Coal Geology". Encyclopedia of Physical Science and Technology. pp. 45–77. doi:10.1016/B0-12-227410-5/00111-3. ISBN   978-0-12-227410-7. Vitrain takes the form of thin, homogeneous bands of black, glassy material, usually ranging from 3 to ∼10 mm in thickness. It is generally very brittle and characterized by a close-spaced fracture pattern cutting across the layers.
3. "Vitrain: Mineral information, data and localities". MinDat. 19 June 2023. Retrieved 11 August 2023.
4. Stadnichenko, Taisia Maximovna; Murata, K.J.; Zubovic, Peter; Hufschmidt, E.L. (1953). Concentration of germanium in the ash of American coals, a progress report. Geological Survey Circular 272. United States Geological Survey. doi: 10.3133/cir272 . hdl:2027/osu.32435030456362.