pennantite

noun

pen·​nant·​ite

ˈpenənt‧ˌīt

plural -s

: a mineral Mn₉Al₆Si₅O₂₀(OH)₁₆ of the chlorite group consisting of basic silicate of manganese and aluminum isomorphous with thuringite

Word History

Etymology

Thomas Pennant †1798 Welsh naturalist + English -ite

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