Chemists - Help Please! (preferably mining/geochemistry)

[Freegs]

Bit of a long shot but I thought i'd ask!

I need the help of a decent chemist to explain a bit about solid solution to me. I am a mining geology student currently nearing completion of my dissertation in which I am investigating an antimony/iron deposit where it appears that antimony is held in solid solution with iron. I am unsure of whether the Fe-rich fluids and Sb-rich fluids were contemporaneous but believe it to be unlikely. Much more likely is that there has been fluidisation of a massive hematite deposit by later, Sb-rich fluids of relatively low temperature (100oC) but high salinity.

A number of questions are presented, notably -

Is it possible that fluidisation has occurred of this hematite/geothite mass at such a low temperature?

Is it possible that Fe/Sb have gone into solid solution in these conditions?

I see it as highly unlikely that the answer to the previous two questions is yes but would greatly appreciate any input from you chemists.
Furthermore, if the answer to both questions is no...what condition would be required to get these two into solid solution and can you point me in the right direction of somewhere I might find out more about the chemical relationship between these two elements?

Cheers!

[Nimby]

Um - lapsed chemist here. I know the melting point of a eutectic mixture is lower than either of the two components, but not that much lower.

Anyway, that's physics!

[V8LM]

Why talk of fluids? A solid solution is where the solvent and solute are both solid. Such would be formed in early Earth history would it not, or a result of volcanic activity.

[Freegs]

V8LM said:

Why talk of fluids? A solid solution is where the solvent and solute are both solid. Such would be formed in early Earth history would it not, or a result of volcanic activity.

Forgive me but Earth's early history is an astonishingly vague term and in fact we are talking about something (relatively) recent but you're right in a sense about volcanic activity. The heat source would be hydrothermal fluids which are carrying the antimony, whether by leaching the bedrock or from the magmatic source.

We are talking about two solids mixing under heat and pressure conditions to coexist as a new crystalline solid within a single crystal lattice. In the case of antimony and iron (whom have different crystal structures) they must mix interstitially rather than substitutionally which, according to Hume Rothery Rules requires the solute to be smaller than the pore space in the solvent lattice.

My questions I suppose is, can anyone point me in the direction of some chemistry resource that will help with determining the mutual solubility of these two elements? That is what I am totally unclear on.

[Nimby]

You need the phase diagram for the two elements.
If that work has been done it will be in one of the chemical abstracts indices. Good luck.