Assertion: biotite | /r/MadeOf | iron
Facets:
value: in the ferrous
type: LOCATION
Source sentences:
text: Iron, it will be seen, is almost completely oxidized in the mica isolated from the upper soil horizons, whereas fresh muscovite and biotite contain iron, predominantly in the ferrous
text: It has been seen that in all the soils studied biotite contains less potash, magnesia, and iron, and more combined water, silica, and alumina than average fresh biotite.