Lampshade,

Form from a geodesic dome/sphere (2v, 80 faces)

For full sphere you need 20pcs of the base-triangle.

For the lampshade you need 10pcs of the base-triangle, 5pcs of the modifyed triangles and the lampfittingplate.

For easy asemmbly i designed the small clips. You need at least 30pcs of clip1, and 10pcs of clip2. Clip2 is only for fixing lampfittingplate to the dome. The clips are pressfit and selflocking.

For security seams need to be superglued from inside, after its assemmbled with clips. After glue is cured, you may choose if you keep the clips or not. My opinion is that they are quite nicelooking.

The base-triangle is one side of the icosahedron (20 faces). 2v means that the sides of the icosahedron sides is divided in two (4 faces), to get more spherical form. I have also modeled a 3v geodesic sphere, wich have alot more faces (180)