Adam August Krantz (6 December 1808 in Neumarkt in Schlesien – 6 April 1872 in Berlin) was a German mineralogist.
August Kranz became one of the foremost mineral dealers in Europe.
Hoffmann sold Krantz's own collection of over 14,000 mineral specimens to the Mineralogisches Museum der Universität Bonn de:Mineralogisches Museum der Universität Bonn and ran the dealership until 1888, assisted by the mineralogist Carl Hintze.
In 1926 his widow Olga took charge of the business, with her nephew, Fritz Krantz.
Fritz had worked for Ward's Natural Science Establishment in Rochester U.S.A.