AM_[K,Na]9[Mg,Fe]2[Mg,Fe,Al,Si]6O12 Formula: Mg1.295 Fe.3 Al1.305 Si1.05 Ca.02 K.28 Na.16 O6 Name: [K,Na].9[Mg,Fe]2[Mg,Fe,Al,Si]6O12 Unit cell: 8.83 8.83 2.779 90.0 90.0 120.0 , V=187.65 Space group: P63/M (176)

Gasparik T , Tripathi A , Parise J B , American Mineralogist , 85 (2000) p.613-618, Structure of a new Al-rich phase, [K,Na].9[Mg,Fe]2[Mg,Fe,Al,Si]6O12,, synthesized at 24 GPa