Crystal Structures of Ideal, Ordered Two-Layer Micas.
Environmental research papers,
AIR FORCE CAMBRIDGE RESEARCH LABS HANSCOM AFB MASS
Pagination or Media Count:
In minerals exhibiting cation disorder, the variation in crystal structure environments can be studied by constructing model structures for all possible cation distributions. The model structures are constructed using known interatomic distances with the computer algorithm DLS distance least squares. For two-layer mica polytypes, the number of possible ways of distributing Si and Al over the 16 tetrahedral sites is large 1820 for SiAl 3 as in muscovite and 12,870 for SiAl 1 as in margarite. It is not feasible to compute DLS structures for all these models, so both populations have been sampled on a random basis to provide 100 cases each for muscovite 2 M sub 1 and margarite 2 M sub 1.
- Geology, Geochemistry and Mineralogy