Werner, Abraham Gottlob (1749–1817)

German geologist, one of the first to classify minerals systematically. He also developed the later discarded theory of neptunism – that the Earth was initially covered by water, with every mineral in suspension; as the water receded, layers of rocks ‘crystallized’.

Werner was born in Silesia and studied at the Mining School at Freiberg, Saxony, and the University of Leipzig. From 1775 he taught at the Freiberg Akademie.

Werner's geology was particularly important for establishing a physically based stratigraphy, grounded on precise mineralogical knowledge. He linked the order of the strata to the history of the Earth, and related studies of mineralogy and strata.