from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Containing iron and magnesium.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. That contains both iron and magnesium
from The Century Dictionary and Cyclopedia
- Containing both iron and magnesium: applied to minerals and also to rocks.
Sorry, no etymologies found.
Many of the latter are magnetite, while the others are hornblende and various ferromagnesian silicates.
Aboriginal Remains in Verde Valley, Arizona Thirteenth Annual Report of the Bureau of Ethnology to the Secretary of the Smithsonian Institution, 1891-92, Government Printing Office, Washington, 1896, pages 179-262
This alteration consists of quartz veinlets, clays, sericite, pyrite, and iron-oxides replacing feldspar, ferromagnesian minerals and plagioclase.
Although ferromagnesian silicate spinels (such as ringwoodite) were later found to break down to simple oxides or stishovite plus perovskite, several post-spinel oxides experimentally convert into a single phase with the CaFe2O4-type and CaTi2O4-type structures.