Antique Engraved Victorian Era Locket Pendant

We suspected this is either silver or silver-plated, but a home acid test came back negative. It appears to have never been used to hold a photo inside, although the front does have a scratch and signs of use. The back has a wonderful patina on the decorated sunken edges and a floral pattern on the locket case. To open it, one must find the small fingernail slip on the left side. 
 
This came to us from a well-traveled American who came from a long line of well-traveled adventurers. 
 
Pendant only H 1/4” x W 1” x D 1/8”
Approx. 0.1 oz
 
Disclaimer: We have tried to make sure colors shown in photos are representative of the real colors of each item. We have tried to identify all imperfections in descriptions, but we may have missed some. If you are unhappy with your purchase, let us know.