large native American turquoise sterling silver belt buckle

Description

wonderful native American sterling silver belt buckle with a beautiful turquoise center stone the piece is signed N?  not sure of the second letter please determine who the artist is for yourself since I am not positive I cannot tell you the tribe this piece came from to me it looks Navajo but please determine for yourself if you know who the artist is would love your help has it's original patina I have not cleaned the piece I took photos in bright light as well as regular lighting to give you accurate pitchers all jewelry will be shipped in a box