American Indian Navajo bracelet, silver with unique green single stone

Nice early Navajo bracelet with single green stone. Bracelet consists of two heavy twisted wire bands, and a single central square band. Nice twisted wire accents surround the bezel and side plates. Stone measures 1 3/4 inch x 1 3/8 inch. 6 1/2 inch inside circumference. Not sure what the stone is. Has a very pale green translucent look to it. My guess to age is somewhere in the 40's. As it's not stamped sterling or with a makers name. $6.00 shipping. PayPal in 48 hours. Thanks!