1970's Bisbee turquoise ring

1970's Vintage Navajo ring. Handmade of sterling silver with genuine Bisbee turquoise. Its rare to find ring like this that has never been worn. The ring measures  1" x 5/8" . The simple setting shows off the Bisbee turquoise stone perfectly.
-“Bisbee Blue” is a name that originates from the Bisbee Mine, near Bisbee, Arizona, in Cochise County, USA. The term refers to the turquoise that comes from copper mines in this region. Turquoise from Bisbee has a reputation as a hard, finely webbed stone with high blue color, ranging from sky blue to a dark lavender blue. The matrix patterns vary a great deal but can be characterized by the deep chocolate brown to black webbing. The hardness is 4.5 on the mohs scale.