It is a penannular kilt pin.
Originally worn by Romans as a brooch to secure cloaks, they were adopted by Scots and Irish to secure Kilts and, continue in use today.
I dont remember. .But I found alot of King George's at that site also..So who knows..
The penannular kilt brooch gets my vote. Here are some variations ...
<img src="http://www.treasurenet.com/forums/attachment.php?attachmentid=1046601"/>
http://s183.photobucket.com/user/JohnSenWint/media/KiltBrooch_zps85cd548e.jpg.html