dragonfly pin

I found this pin at a flea market a long time ago .......on the back it looks like a R stamped in a circle not for sure because my eye isn't the best....i am trying to find out more about my little pin.... maybe what that R would mean?? i have no idea if its real stones....i have had it for at least 25 years i have never cleaned it..it hasn't tarnished at all ....if anyone might know any history on my friend i would love to learn more about him..thank you I hope everyone is having a wonderful day!