noun pin·no·ite \ˈpinəˌwīt\

Definition of pinnoite



  1. :  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)

Love words? You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Join MWU now and get access to America’s largest dictionary, with:

  • 300,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Origin and Etymology of pinnoite

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

Seen and Heard

What made you want to look up pinnoite? Please tell us where you read or heard it (including the quote, if possible).


a brief usually trivial fact

Get Word of the Day daily email!