[Rockhounds] Scapolite again

[DonH]

> It would also look like (my laymen's interpretation ;-))) that annealing
> over long geological periods would permanently differentiate the Al and Si
> in the structure so that the T1-sites become virtually pure SiO4 while the
> T2 sites become highly ordered alternating SiO4-AlO4 rings. 
> I don't see a direct connection with what I'm looking for but I would be
> inclined to think that it might be rewarding to compare meionite specimens
> coming from really big, slow cooling intrusions with those from smaller
> metamorphic regions.


Now you're thinking like a mineralogist.  I still can't predict the 
answer, but your course of investigation would be on the right track.

Given enough time, structures will seek to resolve into the most stable 
coordination scheme, with the lowest potential energy (in general).


Don