(mineralogy) The mineral arsenopyrite.

(physics) A minor stable isotope of iron, ⁵⁴₂₆Fe, having 26 protons and 28 neutrons; it amounts to about 6% of the element in nature

(physics) A minor stable isotope of iron, ⁵⁷₂₆Fe, having 26 protons and 31 neutrons; it amounts to about 2% of the element in nature

(physics) A minor stable isotope of iron, ⁵⁸₂₆Fe, having 26 protons and 32 neutrons; it amounts to about 0.3% of the element in nature

A length of iron or steel, having an L-shaped cross section, used as a structural support

(physics) The major stable isotope of iron, ⁵⁶₂₆Fe, having 26 protons and 30 neutrons; it amounts to about 92% of the element in nature

Any of a group of bacteria that oxidize ferrous iron to ferric iron

(military) (formerly) the second highest military decoration of Germany, under the military order of the Pour le Mérite, or the cross pattée shape of this decoration.

(metallurgy) An allotropic form of iron which is stable at high temperatures. It is used in the manufacture of austenite.

Alternative spelling of gamma iron.