jacobsite

noun

ja·​cobs·​ite

ˈjākəbˌzīt sometimes -kəpˌsīt

plural -s

: a black magnetic isometric mineral MnFe₂O₄ consisting of an oxide of manganese and iron and constituting a member of the magnetite series

Word History

Etymology

French jakobsite, from Jakobsberg, Sweden, its locality + French -ite

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