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jacobsite

noun ja·cobs·ite \ ˈjākəbˌzīt sometimes -kəpˌsīt \
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Definition of jacobsite

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

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Origin and Etymology of jacobsite

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

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