ferrous vs. ferric

ferrous vs. ferric: What's the difference?

Ferrous and ferric both describe something made of or containing iron, with ferrous the more common adjective. In chemistry, the distinction between the endings -ic and -ous is utilized generally to refer to a higher (-ic) or lower (-ous) valence. Therefore, ferrous refers to iron having two valences, and ferric refers to it with three.