Rose, Gustav (gŏsˈtäf rōˈzə) [key], 1798–1873, German mineralogist. He served as professor at the Univ. of Berlin from 1839. Noted especially as a crystallographer, he advanced the scientific study of rocks. His brother, Heinrich Rose, 1795–1864, an analytical chemist, was professor at the Univ. of Berlin from 1823. He demonstrated (1844) that niobium (columbium) and tantalum are different elements.