magnetite

noun mag·ne·tite \ ˈmag-nə-ˌtīt \

Definition of magnetite

: a black isometric mineral of the spinel group that is an oxide of iron and an important iron ore

Recent Examples of magnetite from the Web

There is some magnetite in the limestone, so this alternative mechanism can’t be ruled out.

— scott k. johnson, Ars Technica, "New evidence would push life back to at least 3.95 billion years ago," 30 Sep. 2017
One of the most likely non-biological ways to make lookalike graphite is a reaction of iron carbonate that produces magnetite and graphite.

— scott k. johnson, Ars Technica, "New evidence would push life back to at least 3.95 billion years ago," 30 Sep. 2017
Kiruna sits on top of Kirunavaara, the world’s largest underground iron-ore mine and the source of a rare, high-quality magnetite processed into blueberry-size pellets and used in BMWs and iPhones.

— josh dean, Bloomberg.com, "How to Move a Town," 5 Sep. 2017
What’s more, magnetite crystals produced by bacteria have a distinctive string-of-pearls formation that was not found in the meteorite.

— National Geographic, "NASA’s Bold Plan to Hunt for Fossils on Mars," 17 Oct. 2016
What’s more, magnetite crystals produced by bacteria have a distinctive string-of-pearls formation that was not found in the meteorite.

— National Geographic, "NASA’s Bold Plan to Hunt for Fossils on Mars," 17 Oct. 2016
Magnetotactic or magnetic bacteria have extremely small crystals of magnetite inside their bodies.

— stephen leahy, WIRED, "Power Up With Magnetic Bacteria," 12 May 2006

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'magnetite.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.