Octahedron

grabcad

For this model I created a square on the top plane, and made two planes 10mm above and below the top plane. On those two planes, I made a sketch of a singular point on the origin, then used the lofted boss/base. Note: When I used the loft boss/base I had to do it one at a time.Mass = 0.67 gramsVolume = 666.67 cubic millimetersSurface area = 447.21 square millimeters