Why the color of the iron oxide yellow iron oxide green difference?

         Why the color of the iron oxide yellow iron oxide green difference
         Iron oxide red,iron oxide black,iron oxide,iron oxide yellow,iron oxide brown,ferric oxide blue green equivalent as part of the iron oxide pigments,as oxide,why will present different color?In this paper,the resolution for you the most similar two pigments,iron oxide yellow,iron oxide green color why different?
         Formula for different lead to iron oxide yellow iron oxide green color
         The formulas for iron oxide yellow Fe2O3,crystal mainly Fe3 and O2-.Iron oxide green formula for FeO,crystal mainly Fe2 and O2-,Fe3 is yellow,Fe2 is green,it is obvious that the formula for different led to the two different colors.
         Speaking of which,people will wonder,Fe2 in aqueous solution is green,in the crystal?There in the literature that iron oxide with water of crystallization is the formula for green chemical formula:Fe2O3?H2O,as a kind of inorganic pigments,iron oxide red,iron oxide green,iron oxide yellow exists in the form of crystal,their color mechanism is varies because of its crystal structure?
         In fact,there is the possibility that,this and the complexes of ligand of Fe2,such as hemoglobin is red.And the crystal structure,it is generally believed there will be a reflection and refraction effect,but to the wavelength of the photon seems to have no effect.Complexes of Fe2 and Fe3 electronic level interval changes,energy level transition to release the energy of the photon is different because of the color of the commonly seen,is an inspired by light,and then return from high level to low level,the release of the photon wavelengths within the scope of human vision,can see color.

By Nicole