a very common black iron oxide mineral, Fe3O4, that is strongly attracted by magnets: an important iron ore.

Origin of magnetite

1850–55; magnet + -ite1; compare German Magnetit Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for magnetite

Historical Examples of magnetite

  • There is some sericite present, also magnetite, resulting from the decomposition of the biotite.

  • The minerals at contact are quartz, biotite, magnetite and hornblende.

  • It is also somewhat stained by the decomposition of the magnetite.

  • Most of the ores obtained in Pennsylvania and New York are magnetite.

    Commercial Geography

    Jacques W. Redway

  • The usual association with apatite and magnetite crystals is noted.

British Dictionary definitions for magnetite



a black magnetic mineral, found in igneous and metamorphic rocks and as a separate deposit. It is a source of iron. Composition: iron oxide. Formula: Fe 3 O 4 . Crystal structure: cubic
Derived Formsmagnetitic (ˌmæɡnɪˈtɪtɪk), adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for magnetite

magnetic iron ore, 1840, from German magnetit; see magnet + -ite (2).

Online Etymology Dictionary, © 2010 Douglas Harper

magnetite in Science



A brown to black mineral that is strongly magnetic. It crystallizes in the cubic system and commonly occurs as small octahedrons. Magnetite occurs in many different types of rock and is an important source of iron. Chemical formula: Fe3O4.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.