Antique Art Deco Glass Brooch

This antique/edwardian brooch is made of a gold tone metal (possibly 9k gold) in an art deco style. It has three small purple glass stones, each inside a geometric shape outline. The brooch has an old-style coiled c closure and is stamped C.T. on the clasp, but I have not been able to identify the maker. This piece has some wear from years of use, but it is in good condition overall considering the age. Dimensions: 45mm x 11mm Weight: 2.23g