Let us compare; Dyckia Fantasma and Dyckia white snow, both hybrids I made here.

Above: Dyckia Branca de Neve (Snow White) 

Dyckia goehringii super white form X Dyckia Brittle Star

Bellow: Dyckia Fantasma (ghost)

Dyckia goehringii super white form X Dyckia fosteriana suoper white form