\begin{pspicture}(-4,-4)(4,4)
\psset{lightsrc=50 30 20,viewpoint=20 10 5,Decran=50}
\psset{solidmemory}
\psSolid[object=octahedron,
   a=2,
   trunc=all,
   hue=.5 .6,
   trunccoeff=.3333,
   name=my_octahedron,
   action=draw*]
\psSolid[object=point,
   definition=solidgetsommet,
   args=my_octahedron 0,
   fontsize=20,
   text=A,
   pos=cl,
]
\psSolid[object=point,
   definition=solidgetsommet,
   args=my_octahedron 1,
   linecolor=red,
   fontsize=20,
   text=B,
   pos=uc,
]
\psSolid[object=point,
   definition=solidgetsommet,
   args=my_octahedron 2,
   linecolor=red,
   fontsize=20,
   text=C,
   pos=ur,
]
\psSolid[object=point,
   definition=solidgetsommet,
   args=my_octahedron 3,
   linecolor=red,
   fontsize=20,
   text=D,
   pos=ur,
]
\composeSolid
\end{pspicture}