Citation: Armbruster, T.; Oberhansli, R. (1988). Crystal chemistry of double-ring silicates: Structural, chemical, and optical variation in osumilites Sample: Eifel-Nickenich. American Mineralogist, 73, pp. 585-594.
Formula: Al4.56 Fe0.26 K0.69 Mg1.98 O30 Si10.2
List type: noninterleaving
List: 3D
Basis: (1;0;0 0;1;0 0;0;1)
Dimensionality: 3
Formula: Al30 Fe10 Mg4 O60 Si24 (Al15 Fe5 Mg2 O30 Si12)
Multiplicity: 1