Cosmic flakes belong to the category of cosmic microparticles. They occur together with cosmic spherules in sediments (Utech, 1965). These flakes appear to represent ablation products of iron meteorites burnt away during the passage of a meteorite through the atmosphere by friction against air molecules. Microprobe analyses offtakes from deep-sea deposits proved the particles to consist of magnetite which in most cases had been altered into maghemite in the outer zones. This is in agreement with the assumption that they represent fragments of fusion crust of iron meteorites. Most of the flakes, however, contained a small percentage of manganese. This element is not a common constituent of iron meteorites. The author attempts to explain the presence of manganese in flakes and its absence in cosmic spherules.