Summary of minerals with AX6 coordination group structures .
    Here again the packing arrangement of the close packed X atoms and the percent
occupation of the interstitial voids determined the number and types of linkage
surfaces of the AX6 coordination groups of minerals and their chemical composition. .
The number of octahedral interstices in a crystal structure is equal to the number of .
close packed atoms.  Hence the chemical formula for structures with a given percent .
occupation rate of their octahedral voids can be deduced a priori.













2/3 (66.7%)








1/3 (33.3%)







Table 7 -  Percent occupancy versus formula for AX6 mineral structures

     The following section also establishes the structural basis for the chemical .
composition of minerals with interstitial atoms occupying both octahedral and
tetrahedral voids, as well as cubic and trigonal prismatic interstices.

Back to mineral table

Back to Knowhere

Home page

page 67 of lesson

Page  68 - Structure matters - Octahedral summary

page 69 of lesson


home   sitemap   products   Polywood   .networks   contact us   Knowhere   3Doodlings