Rare Vintage Sterling Silver Turquoise Bracelet Navajo Signed R Ster Kingman

This is a vintage Native American Navajo cuff bracelet made of sterling silver and turquoise gemstone. The bracelet is signed “R Ster” and is believed to be from the Kingman mine. The turquoise stone is set in a bezel setting and the bracelet has a unisex design. Was my grandma’s. She is now 85 years old. I don’t know for sure but this seems to be from the kingman mine. Please message with questions or concerns. I will usually respond within 24 hours.