pinnoite

noun

pin·​no·​ite

ˈpinəˌwīt

plural -s

: a hydrous magnesium borate Mg(BO₂)₂.3H₂O usually occurring in yellow nodular masses with a radiating fibrous structure (hardness 3–4, specific gravity 2.3)

Word History

Etymology

German pinnoit, from Pinno, 19th century German mining official + German -it -ite

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