KS8440 Inverse Spinel Crystal Model
Inverse SpinelSpinel is the name given to the mineral MgAl2O4. It has a common structural arrangement shared by many oxides of the transition metals with formula AB2O4. In the normal pattern the oxygens (red) form a cubic close packed (ABCABC or face centred) array and the Mg(II) (A(II)-green) and Al(III) (B(III)-silver) sit in tetrahedral (1/8 occupied) and octahedral (1/2 occupied) sites in the lattice, giving a Unit Cell with 8 Mg's, 16 Al's and 32 O's. An inverse spinel is an alternative arrangement where the divalent ions swap with half of the trivalent ions so that the M(II) now occupy octahedral sites i.e. B(AB)O4. In this case Ni(II) is octahedral and half of the Fe(III) are tetrahedral. Complexes that share this structure include.. a number of 1st row TM oxides and sulfides.
This model is hand made in the USA by Klinger Educational Products. This is a permanent structure. We only use grade A materials. The 1 inch balls are made of hard Maplewood that includes an enameled painted finish. Polished steel rods are used to connect the wooden balls together.
Inverse Spinel contains 114 - 1 inch balls.