Jöns Jacob Berzelius
Cronstedt noted in "Försök til mineralogie, eller mineral-rikets upställning" that he had observed an “unidentified earth” in a heavy red stone from the Bastnäs mine in Riddarhyttan. Forty-five years later, Jöns Jacob Berzelius and Wilhelm Hisinger isolated the first element of the lanthanide series of the rare earth elements, cerium, in ore from the mine.