glutSolidOctahedron man page
glutSolidOctahedron — Draw a solid octahedron.
OpenGLUT - geometry
This function draws a regular, solid 8-sided polyhedron centered at the origin. The vertices are at (+/-1, 0, 0), (0, +/-1, 0), (0, 0, +/-1).
We visit the same vertices the same number of times as in the wire octahedron, but the order is different.