For each of the earrings, I've set a vintage glass foilback cabochon in a serrated bezel on a sterling silver post. The cabochons were made in Germany in the 1960s. Violet, smoky, and opaline measure 12x10mm; pink are 8x10mm; blue are 14x10mm. I've oxidized the settings to give them a dark shine.
These earrings will arrive all boxed up and ready to be given as a gift (or kept). The last photo shows my packaging (earrings not included, of course).