Definition of pinnoite in US English:

pinnoite

noun

Mineralogy
  • A yellow or yellowish-greenish mineral which is a hydrated borate of magnesium, MgB₂O₄·3H₂O, occurring as translucent crystals of the tetragonal system or granular masses.

Origin

Late 19th century; earliest use found in American Naturalist. From German Pinnoit from the name of M. Pinno, chief councillor of mines in Saxony, where the mineral was found + -it.

Pronunciation

pinnoite

/ˈpɪnəʊʌɪt/