This was an estate sale find and I was told this one and the other five I purchased were antique from the late 1800's. There is a stamp of "900" on it. I googled the topic and the info I found is pasted below for your information.
This hand hair pin is 3.25 inches long and in good condition. Weighs 4.61 grams

What is 900 sterling silver?
900 silver, or 90% silver and 10% copper. The name "coin silver" is because metalsmiths historically made items from melted down scrap coin metal. At the time the name was given, coins were made from more precious metal than today.  
When was 900 silver used?  Prior to 1870, the silver standard in the USA was “coin silver” (900/1000) which is slightly lower than sterling (925/1000) silver