Chromite, an iron-chromium oxide (FeCr2O4), is a mineral belonging to the spinel group of minerals. Magnesium can replace iron in varying percentages to form a solid solution of chromite and magnesiochromite. Chromites are formed at greater subsurface depths in rock suites such as peridotites, ultramafic intrusives and high-grade metamorphic rocks. Chromite and magnesiochromite are the practically unique ores of commercial chromium. The black fragments of chromite in this specimen are seen interspersed in light green serpentine. Sample from Guleman mine in Eastern Turkey, actual width is 120 mm.