Fabricated Sterling. Approximately 2 1/2 inches.
This is my take on the traditional Bavarian/Austrian hat pin. I altered the traditional shape and the fastening mechanism.
The pin is designed to hold either a feather or a bundle of hair (goat and badger are typical). It is held in place with a screw.
The downy feather is from a peacock. I found it at a zoo.
Here is the pin and its pieces.
The threaded points are inserted into the hat, and the round nuts secure it from inside the hat.