Moore, Paul B. Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois.
Last reviewed:August 2020
Show previous versions
- Related Primary Literature
- Additional Reading
A cubic mineral and member of the spinel structure type, space group Fd3m, with composition [Fe3+]IV[Fe2+Fe3+]VIO4. It possesses the inverse spinel structure, in which half the ferric iron is tetrahedrally coordinated and the remaining half as well as all ferrous iron are octahedrally coordinated by the cubic close-packed oxygen atoms. The color is opaque iron-black and streak black, the hardness is 6 (Mohs scale), and the specific gravity is 5.20. The habit is octahedral (see illustration), but the mineral usually occurs in granular to massive form, sometimes of enormous dimensions. Though possessing no cleavage, some specimens show an octahedral parting. Limited Al3+ may substitute for Fe3+; and Ca2+, Mn2+, and Mg2+ for Fe2+.
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 10,000 highly qualified scientists and 46 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information