Magnetite and Rust

[BillyJoe]

There are many other forms of Iron Oxide but the three of interest here are:

ferrous oxide: FeO [Iron (II) Oxide] [Wusite]
ferric oxide: Fe2O3 [Iron (III) Oxide] [haematite] [rust]
ferrous ferric oxide: FeOFe2O3 or Fe3O4 [Iron (II,III) Oxide] [magnetite]

I was wondering why Randi had magnetite written as FeFe2O4, instead of either of the two more logical versions FeOFe2O3 or Fe3O4



Incidentally I cannot find anything called Iron (I) Oxide

[Slimething]

I was wondering why Randi had magnetite written as FeFe2O4, instead of either of the two more logical versions FeOFe2O3 or Fe3O4

I found this here (http://www.galleries.com/minerals/oxides/magnetit/magnetit.htm):
Magnetite is a member of the spinel group which has the standard formula A(B)2O4.

I also found a lot of other physical chemistry-type sites where magnetite is written as FeFe2O4. I'm not an inorganic chemist so this type of notation is also unfamiliar to me but it seems that those who study the electronic nature of this mineral prefer this notation. I am guessing (too tired to do the research) that this mineral is not really
Fe3O4 but, rather, an inhomogenous mixture of two forms of iron oxide.

Incidentally I cannot find anything called Iron (I) Oxide

Iron does not have a (stable) oxidation state of +1. I believe there must be a coordination bond between the iron in FeO and one of the oxygen atoms in Fe2O3.

[Soapy Sam]

Incidentally I cannot find anything called Iron (I) Oxide


I think you have to be very quick...

[BillyJoe]

I found this here (http://www.galleries.com/minerals/oxides/magnetit/magnetit.htm):


Magnetite is a member of the spinel group which has the standard formula A(B)2O4.


I also found a lot of other physical chemistry-type sites where magnetite is written as FeFe2O4.


It seems Randi hit upon the conventional designation then.
I suppose it is a logical way to write it if you want to more clearly identify it with its group

I am guessing...that this mineral is not really
Fe3O4 but, rather, an inhomogenous mixture of two forms of iron oxide.


The link seems to say otherwise:

"The A and B represent usually different metal ions that occupy specific sites in the crystal structure. In the case of magnetite, Fe3O4, the A metal is Fe +2 and the B metal is Fe +3; two different metal ions in two specific sites."

Iron does not have a (stable) oxidation state of +1. I believe there must be a coordination bond between the iron in FeO and one of the oxygen atoms in Fe2O3.


I get the bit about Fe+
However in FeO it is Fe++ and in Fe2O3 it is Fe+++, so I'm not sure how your second sentence relates to Fe+.

[BillyJoe]

I think you have to be very quick...


Yeah, gotcha. ;)

[Slimething]

However in FeO it is Fe++ and in Fe2O3 it is Fe+++, so I'm not sure how your second sentence relates to Fe+.

You're right. :o

[tracer]

ferrous oxide: FeO [Iron (II) Oxide] [Wusite]

Aw, what a shame. I mean, how would YOU like to be called "wussite"?

[AudioFreak]

I love rust... especially when it's ground finely and glued to a 2" wide strip of tape. I <3 2" mag tape.

[BillyJoe]

You've got to give it to rust. It never sleeps.

[RSLancastr]

Magnetite and Rust was a failed Joan Baez song.

Later she renamed it and it fared much better.

[BillyJoe]

Neil Young had a live album called "Rust Never Sleeps" and he recycled it as lyrics in the opening and closing numbers "My, my, hey, hey" and "Hey, hey, my, my".