Vintage Enamel Geometric Brooch

This vintage brooch is made of gold tone metal and has a modern locking c pin closure. The front of the brooch has geometric shapes outlined by gold lines and filled with red and purple tone enamels. The back appears to be stamped "AV" in a small diamond shape, but I have not been able to find the maker. There is some tone loss on the back (but not the front) and the pin is very slightly bent, but the brooch does not have any issues that affect wearability. Dimensions: 46mm x 33mm Weight: 18.31g