code: def icosahedron():
      
      t = (1.0 + 5.0**.5) / 2.0
      vertices = [-1, t, 0, 1, t, 0, -1, -t, 0, 1, -t, 0, 0, -1, t, 0, 1, t,
                  0, -1, -t, 0, 1, -t, t, 0, -1, t, 0, 1, -t, 0, -1, -t, 0, 1]
      faces = [0, 11, 5, 0, 5, 1, 0, 1, 7, 0, 7, 10, 0, 10, 11,
               1, 5, 9, 5, 11, 4, 11, 10, 2, 10, 7, 6, 7, 1, 8,
               3, 9, 4, 3, 4, 2, 3, 2, 6, 3, 6, 8, 3, 8, 9,
               4, 9, 5, 2, 4, 11, 6, 2, 10, 8, 6, 7, 9, 8, 1]
      # scale vertices so each vertex radius is 1.0
      vertices = np.reshape(vertices, (-1, 3)) / np.sqrt(2.0 + t)
      faces = np.reshape(faces, (-1, 3))
      mesh = Trimesh(vertices=vertices,
                     faces=faces,
                     process=False)
      return mesh
docs: Create an icosahedron, a 20 faced polyhedron.
  
      Returns
      -------------
      ico : trimesh.Trimesh
        Icosahederon centered at the origin.