Let me refine the “machinery” of the calculations first; I’ll then focus on the user input. The latter is more likely to produce intractable problems. If that ends up being the case, then I’ll at least have produced code that I can use for my own purposes
![Grin ;D](https://probesoftware.com/smf/Smileys/default/grin.gif)
. Perhaps I’ll ask “
other Brian” for some advice.
I took a look at the amphibole code written by Ague -- he is using essentially the same approach that I outlined briefly above (the list of possibilities is not very long). I haven’t looked at his code closely enough, but it looks like he may be using an average of stoichiometrically allowable Fe2O3/FeO calculations in a manner similar to Holland and Blundy* (1994, CMP 116:433-447, Appendix B -- attached); if so, this is bad practice. I haven’t looked at the biotite code yet.
I’m hoping to make some headway on this in the next week or two. My workload has been brutal for the past several months, but I think I can see light at the end of the tunnel (or is it just an illusion?).
*I don't like their use of "average Fe2O3" (p. 436) because, even if a recalculation is stoichiometrically allowable, this doesn't necessarily mean that it is geologically reasonable. Still, Holland and Blundy give a nice, compact summary of the various amphibole recalculations in Appendix B.