Native American silver ring with petrified wood center vintage Native American buy ring Native American jewelry

Vintage Native American ring. There are some markings but I don't know what they mean. Silver setting with scalloped edge and rope design around a large oval petrified wood. There is one nick in the stone (see photos) which I believe is a natural occlusion. According to ring sizer, size 6, see photos.
Focal point of ring measures 1 1/4 inch by approximately 3/4 inch .