| Abstract: | The absorption spectra of 36 natural garnets formed under different conditions have been investigated. The results show that the [CrO6] complex has the symmetry m3m only if the minerals crystallized under extreme conditions, expecially at high pressures and high Cr2O3 concentrations. Mostly the microsymmetry 4 mmm has been observed for the octahedral complexes. Corresponding to theoretical calculations based on the crystal field theory it is revealed by comparison of intensities that [CrO6] is essentially more stable than [FeO6] complexes. Garnet reacts under energy supply to pyroxene (bronzite) and to complex oxidie phases as shown by further studies. |
