I have owned several of these Hattie Carnegie Herons before- They can be signed or unsigned. They are identical. This one is unsigned.
Value is $399.00- $700.00 in the past.
This heron brooch is finished in heavy gold plated metal. The head and middle body are made of a colored textured thermoplastic. The wings are white enamel with clear crystal rhinestones. He has a green eye.
The item is 3" long by 1" wide. It is in excellent condition.
Ref: Classic American Costume Jewelry, V2 p 21 by Jackqueline Rehmann,Collector Books 2011