The present invention relates to pigments, comprising a plate-like substrate of perlite which does not contain 3D twin structure particles contained in milled expanded perlite in an amount of greater than 5% by weight., and (a) a dielectric material, especially a metal oxide, having a high index of refraction； and/or (a) a metal layer, especially a thin semi-transparent metal layer； a process for their production and their use in paints, ink-jet printing, for dyeing textiles, for pigmenting coatings (paints), printing inks, plastics, cosmetics, glazes for ceramics and glass.
