Garnet typically has the chemical formulat (fe^2+, mg^2+, ca^2+, mn^2+)_3 al^3+_2 si^4+_3 0_12. the formula can be broken up into structural sites (spaces where cations of a certain size range occupy) x_3y_2z_3o_12 where the x-site is coordinated with 8 oxygen anions, the y-site is coordinated with 6 oxygen anions, and the z-site is coordinated with 4 oxygen anions. calculate the predicted coordination number (cn) relative to o^2- for each cation in the garnet formula. how do the calculated cns compare to those for real garnet? explain why they are the same or different.