This is such a magnificent earring and I have just a few made from an exceptions small batch of green amethyst stones. They are cabochon on the front of the stone and faceted at the back. Some have pretty green peridot at the top, like this one here, there are a few with a small pink tourmaline instead. I must take picture of that one too.
Set in Sterling silver approximately 16mm square, this is understated elegance at its best.