Absolutely gorgeous! Made in France, these lovely earrings have an Art Deco feel to them. To be perfectly honest, they are sort of a mystery. They are hallmarked PLAQUE OR, LAMINE which translates as rolled gold plated. There is also another very small hallmark that is either the French mark for 18k, or for imported gold. It unfortunately is too small for me to photograph clearly. I have not been able to date these. They could be as early as 1930's or as late as 1970's. Nevertheless, they are exquisite!
The top part looks like a ribbed crescent moon with the large pear shaped amethyst glass stone below. The clip mechanism is very similar to that used by Louis Rousselet.
These are in excellent condition, they look like they were hardly worn. They measure 2 inches long.