Band Gap of Forsterite

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Science  05 Jul 1968:
Vol. 161, Issue 3836, pp. 51-53
DOI: 10.1126/science.161.3836.51


Optical absorption and reflectivity measurements on synthetic forsterite show that this silicate has a wide band gap of the order of 8.4 electron volts; thus it resembles other pure insulating oxides such as MgO. For natural olivines, in which divalent cations, mainly Fe2+, can replace Mg2+, all the optical absorption bands between the lattice overtones in the infrared and the first excitonic transition at 8.4 electron volts are due to the presence of iron.