Min. [f. Jakobsberg, place-name + -ITE.] An oxide of iron and manganese, belonging to the spinel group, found at Jakobsberg in Sweden.
1869. Latest News, 17 Oct. Jacobsite is a new mineral described before the French Academy of Sciences by M. Damour.
1872. Dana, Min., App. i. 8. Jacobsite … does not lose weight when ignited.
