Great Grandma or Great Great Grandma's, or...?

This unique beautiful little fan was found in an old box of misc. items of my great uncle's. He never married. I would like to figure out the time period for this fan. I have been unable to find any fans like this one. It's possible it had been his mothers', or grandmothers as each generation took care of the previous generation and so they're things were sometimes randomly put away and stored together. He had long family history that so far I've traced our America roots to before the Revolutionary War. With the help of a magnifying glass, I have found the clasp to say "Patented". I'm pretty certain the guard is tin and the clasp is brass. Any suggestions on where to research would be appreciated.