magnetite
Noun
Meaning
An oxide of iron (Fe3O4) occurring in isometric crystals, also massive, of a black color and metallic luster. It is readily attracted by a magnet and sometimes possesses polarity, being then called loadstone. It is an important iron ore. Called also magnetic iron.
Source: Webster's dictionarySynonyms
Hypernyms
Phrases with the word
Examples
It has a spinel -like structure similar to magnetite but uses one quadravalent and two divalent cations M 2 +2 M +4 O 4 instead of two trivalent and one divalent cations.
An example is magnetite (Fe 3 O 4 ), which contains Fe 2+ and Fe 3+ ions with different magnetic moments.
In industrial practice, the iron catalyst is obtained from finely ground iron powder, which is usually obtained by reduction of high purity magnetite (Fe 3 O 4 ).
In rhyolites and trachytes, early crystals of hornblende and biotite may be found in great numbers partially converted into augite and magnetite.
It has since been shown that similar magnetite structures can form without the presence of microbial life in hydrothermal systems. citation A few meteorites were found in Antarctica between 1912 and 1964.
Modern ammonia-producing plants depend on industrial hydrogen production to react with atmospheric nitrogen using a magnetite catalyst or over a promoted Fe catalyst under high pressure (convert) and temperature (450 °C) to form anhydrous liquid ammonia.