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


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

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Dictionary Entries Near pinnoite

Cite this Entry

“Pinnoite.” Dictionary, Merriam-Webster, Accessed 21 Jun. 2024.

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