Unmarked Silver and Turquoise Navajo Cow Bell Screw Back Earrings

This pair have not been polished as shown in photos, but they are so cute! They feature unmarked silver bells with turquoise bezel-set stones in the center of each. We confirmed they are silver using an acid test. Inside, a little clanger emits a tinkle when the earrings move. 
 
We believe these are mid century Navajo earrings of the Fred Harvey era. 
 
These were found in our grandmother's vintage jewelry collection. We do not know when or where she acquired them.
 
H 1 1/8” x W  1/2” x D 1/4”
Approx. 0.4 oz (11g)
 
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.