This is an absolutely fascinating piece of art glass from the Art Deco era.. I am surprised that it isn't signed, as it is very high quality and appears to be wheel cut?.. The design is wildly geometric and a good representation of high style Art Deco. It is an electric blue heavy crystal (lead) that glows under light. It is 12" in diameter and has a sawtooth treatment to the edge. This dates to around 1925 and is possibly French. The condition is beautiful with minimal wear.