Merriam-Webster Logo
SINCE 1828
Menu
dictionary thesaurus

neptunite

noun
nep·​tun·​ite | \ -ˌnīt\
plural -s

Definition of neptunite

: a mineral (Na,K)2(Fe,Mn)TiSi4O12 consisting of a silicate of iron, manganese, potassium, sodium, and titanium

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!

History and Etymology for neptunite

Swedish neptunit, from Latin Neptunus Neptune + Swedish -it -ite

Keep scrolling for more

Learn More about neptunite

Statistics for neptunite

Look-up Popularity

Comments on neptunite

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

Show Comments  Hide Comments 

WORD OF THE DAY

suffuse

Listen to the pronounciation of suffuse

to spread over or through

Get Word of the Day daily email!

Test Your Vocabulary

The Exceptions Quiz III

  • one green toy robot amidst many red toy robots
  • Which of these words does not mean "nonsense"?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

TAKE THE QUIZ
Syn City

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

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

Words at Play
Ask the Editors
Word Games