Phase composition and structural state of natural iron oxide pigments

Samples of brown and yellow ferruginous ocherous ores and associated slightly ferruginous weathered rocks (the so-called belyaks) taken from deposits of the ZigazinKomarovo iron-ore district in the South Urals were investigated. It may be assumed with high confidence that increase in the size of particles and crystallization degree of these phases results in transformation of spherical semiamorphous Fe-oxihydroxide into euhedral -FeOOH crystallite,i.e., a valuable pigment raw material into typical brownstone ores.