Definition of jacobsite
: a black magnetic isometric mineral MnFe2O4 consisting of an oxide of manganese and iron and constituting a member of the magnetite series
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 jacobsite
French jakobsite, from Jakobsberg, Sweden, its locality + French -ite
Seen and Heard
What made you want to look up jacobsite? Please tell us where you read or heard it (including the quote, if possible).