For his post-doctorate work, Seifert moved to University of Bochum and defended a habilitation thesis in 1970.
He then stayed at the Carnegie Geophysical Laboratory in Washington, DC, where he applied Mössbauer spectroscopy to study the kinetics of the formation of rocks and minerals.
In 1987, he was awarded the Gottfried Wilhelm Leibniz Prize, worth 2.5 million euro.
[1] In 1994, he received an honorary doctorate from the Faculty of Science and Technology at Uppsala University, Sweden.
[3] In 2004, he received the Abraham Gottlob Werner Medal for achievements in the experimental and theoretical petrology and spectroscopy of minerals and silicate melts.