Johann Karl Wilhelm Voigt (20 February 1752 in Allstedt – 2 January 1821 in Ilmenau) was a German mineralogist and mining engineer.
He initially studied law at the University of Jena, then in 1776 enrolled at the Mining Academy in Freiberg as a pupil of Abraham Gottlob Werner.
[1] He later relocated to Weimar, where in 1783 he was named secretary of the Bergwerkskommission (mining commission).
[1] He is best remembered for his dispute with Werner in regards to latter's theory of Neptunism; with Voigt maintaining that basalt was of volcanic origin.
[1] In 1800 he introduced the term "lettenkohle" to describe coal with a large content of letten (regional German word for clay and mud).