Transparent Iron compounds

[Sensei]

Hello!

 

What are known transparent (in visible spectrum) Iron compounds.. ?

 

Best Regards!

 

[John Cuthber]

I doubt there are any fully transparent ones. Something like this

https://en.wikipedia.org/wiki/Iron(II)_sulfate#/media/File:Iron(II)-sulfate-heptahydrate-sample.jpg

or this

https://en.wikipedia.org/wiki/Iron(III)_fluoride

is probably as good as it gets

Why do you ask?

[Sensei]

Why do you ask?

 

Two weeks ago, I took initial Iron compound, and put approximately equal amount of it to 10+ test tubes.

With various 2nd chemical compounds. To quickly check them all at once.

Part of them visible on this photo:

 

Couple days ago I noticed 1st from the left is completely transparent:

 

It used to look like this control sample two weeks ago:

 

The last time I looked at it week ago, there was still tiny tiny amount of initial Iron compound (it was disappearing with time) on the bottom and slightly yellow color of solution.

Now it's practically transparent like pure water.

Edited July 18, 2015 by Sensei

[Enthalpy]

To discolour (or remove?) FeCl₃ stains (from etching printed circuits), fluoride salts are used, or with fewer drawbacks, oxalic acid. Sound a bit like what you describe, but what is the process?

[John Cuthber]

Dilute solutions of Fe(++) in water are only very slightly coloured.

The Fe(+++) complex with fluoride is also very pale.

[Enthalpy]

So removing stains would just mean dilute them with the proper liquid?

[John Cuthber]

So removing stains would just mean dilute them with the proper liquid?

Not really.

If they are a stain they are (almost certainly) a solid so you need to dissolve them.

[Pyrine]

Dunno if it fits the description or what you're looking for exactly, but there are quite a few gemstones that are transparent and even clear as quartz that contain iron as part of their overall chemical compounds.

 

Phosphophyllite is a mineral with a hardness of 4 out of 10 on the Mohs scale of mineral hardness. These Monoclinicly structured gems are made of hydrated zinc phosphate, their full chemical compound being Zn2(Fe,Mn)(PO4)2.4H2O. - See more at: http://gem5.com/stone/88/phosphophyllite/#sthash.c6rVabih.dpuf