Vintage Navajo unmarked sterling silver dangle earrings (pierced ears), beautiful first nation craftsmanship, 5 grams of silver

Vintage Native American First Nation solid silver earrings with a geometric stylised face design and gorgeous long double feather dangles. The earrings are not signed or stamped, but test positive for solid 925 sterling silver. From what I can find from research, I believe these to be more likely to be Navajo pieces than any other such as Zuni made. I am still researching as there seems to be a lot of conflicting labels and, perhaps, misinformation out there on the internet.

They fasten with ear rods and butterfly backs. They were missing a pair of butterfly backs, so I have added the ones in the picture - please note these backs are not sterling silver, but just silver tone. 

The earrings are about 2 inches long and are in very good vintage condition. With the back removed, the pair weighs 5 grams overall.