plural -s
: a clay mineral Al2Si2O5(OH)4.n H2O occurring in soft white or light-colored masses and in at least two states of hydration n =2, n =4

Word History


French, from Omalius d'Halloy †1875 Belgian geologist + French -ite

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.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Dictionary Entries Near halloysite

Cite this Entry

“Halloysite.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/halloysite. Accessed 20 Jun. 2024.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!