Fabre's medium of choice for the work were the iridescent shells of jewel beetles (specifically those of the Sternocera acquisignata). So with the blessing of Queen Paola, Fabre coated the ceiling panels of the Hall of Mirrors along with the central chandelier.
About one and a half million beetle shells were used and even though the photos are fascinating, I have to imagine that the effect when viewed in person is particularly stunning. And all that beauty from a bunch of bugs!
If you'd like to take a quick video tour, you can see that here: