His earlier papers were mostly concerned with crystallography, and the reputation they gained him led to his appointment as Privatdozent at Konigsberg, where in 1828 he became extraordinary, and in 1829 ordinary, professor of mineralogy and physics.
He retired from his professorship in 1876, and died at Konigsberg on the 23rd of May 1895.
Keller, Memel, Pregel and Weichselstrom (2 vols., Berlin, 1900); and Schickert, Wasserwege and Deichwesen in der Memelniederung (Konigsberg, 1901).
It was found in some abundance at the end of the 18th century in the copper mines of the St Day district in Cornwall, and has since been found at a few other localities, for example, at Konigsberg near Schemnitz in Hungary, and in the Tintic district in Utah.
Its eastern limit in Europe is a line from Konigsberg to the Caucasus; thence through China it is continued by varietal forms to Japan.