| The spinels have low Mg number in comparison with Alpine-type peridotites, suggesting hydrothermal alteration in which Cr is preferentially retained in spinel. |
| It grades into a manganese-rich ilmenite that ultimately replaces the spinel phase near the transition to the garnet amphibolite. |
| Chromite, picotite, and magnetite also occur in dunite, as do spinel, ilmenite, pyrrhotite, and platinum in some cases. |
| Peridotite: magmatic rock of color green blacky made up of olivine, pyroxene and spinel with sometimes the presence of biotite and garnet. |
| Results have been obtained recently for a model spinel system formed by a solid solution. |
| Some of the alumina and iron oxide may occasionally be chemically combined, so as to form an iron spinel, or hercynite. |
