I am excited to have found these. Super nice, vintage in great shape. Black glass base and the profile is also glass with an iridescent luster to it. Looks like mother of pearl, which is what they were probably going for. It has a flat back but mild bevel on the front and the back edge. Could be a bit fussy on a setting, Probably originally designed for a cinch setting but I think you can make it work in a lot of them. Deeper bezels. prong settings and wire wrapping are a good choice. A vintage piece no longer being produced. Made in Germany,
