This looks like a full moon, it is a very amazing semi precious stone brooch. IT is a beautiful large satin sheened hand carved antique Selenite palmstone. It's structure is beautiful with a pure white grain running through it and when turned, it turns it almost glows.In the last photo with black background I show a photo of the glow on another palmstone because my camera did not catch it on this piece.
When you hold it near any light, beautiful rays of soft glowing areas appear ( like in obsidian). Selenite so called because it is supposed to wax and wane with the moon is named for Selene, Greek goddess of the Moon because of its moon-like glow.
BUT this brooch has a bit of history that was passed on with it. we found it in a beautiful antique carved bible box with an antique teether. It seems it was a brooch for a mother to wear and was hand carved in this stone because it is an excellent crystal for breastfeeding and nurturing a child. Add to that the two carved ACORNs (In Norse and Celtic culture, acorns symbolized life, fertility and immortality).
Examples of oak and acorn jewelry can be found as far back as the 1900th century ( 1800's). I was told this would have been a very spiritual person who wore this and it would have been given to her by her husband who had it hand made. This has a solid gold clasp, pin and all other bands and chains.
This rare treasure is quite large ( 2 1/2" x 1 1/2" and is heavy and extremely well made. I am sure that the owner was probably a very prominent person being as how this is real gold and was hand commissioned.
There is a bale to hang it from a chain or you could wear it as a brooch. I really think this should be a museum piece because it is definitely one of a kind and an example of wonderful Georgian jewelry which was never machine manufactured.