Outstanding Turquoise Ring with Brown Chert Matrix Size 7 3/4

Vintage egg-shaped Navajo turquoise ring in sterling silver. The stone is natural and the tip has turned green from age and exposure. The bottom area is less porous and did not turn green. Gotta love the gradient color. The matrix is brown chert that is mottled in color. The shank is cold chisel split and strong. Size 7 3/4. Face measures 1 3/8" by 1". Weight: 13 grams. No hallmarks. Acid tested.