This came from a shop and is large and heavy - 46cm diameter. it is designed to hang from a ceiling with a hole for a lighting cable to pass through. Metal fixings included but missing a few screws. The onyx has a large paint splash, chips on the edge, and scratches.
May be of interest for restoration.
Large vintage onyx lightshade (Dorridge B93)
This offer has been gifted to someone and is no longer available.