Abstract: The invention relates to a pigment comprising(a) a flat core and(b) at least one coating consisting of at least two different substances that is applied to the surface of the core,whereinthe coating (b) has a substantially continuously variable composition in the axis lying perpendicular to its surface, andthe refractive indices of the coating (b) at the surface facing the core (a) and at the surface remote from the core (a) are different.An outer coating (c) may additionally have been applied to the coating (b). The pigment may be embedded in a high molecular weight organic material, the refractive index of the coating (b) at its surface that is remote from the core (a) and the refractive index of the high molecular weight organic material being different. Preferred embodiments relate to specific refractive index ranges and differences.

Abstract: The invention relates to colored luster pigments consisting of a transparent or metallic reflecting core, of a coating consisting of at least one silicon oxide of the composition SiO.sub.0.25 to SiO.sub.0.95 and of further optional coatings, to coating processes by coating metallic silicon in the presence of oxygen, if required with changing its partial pressure, as well as to the use of these luster pigments for pigmenting plastic materials, paints and printing inks, and to pigmented compositions comprising these luster pigments.