This is a Polifemo floor lamp designed by Carlo Forcolini for Artemide in the 1980s.
It has a black metal frame with a thin vertical stem, a circular base, and a cone-shaped socket that supports a horizontal disc reflector, creating a circular rainbow effect on the ceiling.
Did you know Polifemo is the Italian name for Polyphemus, the famous Cyclops (one-eyed giant) from Greek mythology.