tridymite

noun

trid·​y·​mite
ˈtridəˌmīt
plural -s
: a mineral SiO2 that is a silica, differs from quartz in its usually minute thin tabular orthorhombic forms of crystallization, and is found in cavities in trachyte and similar rocks (hardness 7, specific gravity 2.28–2.33)

Word History

Etymology

German tridymit, from Greek tridymos threefold (irregular from tri- three + didymos twin) + German -it -ite; from its common occurrence in trillings

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 tridymite

Cite this Entry

“Tridymite.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tridymite. Accessed 19 Mar. 2024.

Love words? Need even more definitions?

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