I once made a couple of tiny turned boxes, much easier to turn one than assemble a micro marquetry box. The brass “grail” fits inside.
The most difficult aspect of this one was not dropping the lid when parting it off from the lathe. Once it hit the bench or floor is was lost forever. The diameter of this one is 0.009" or about three times the thickness of an average sheet of paper.
Troy in Melrose Florida